Every week through the off-season NFL expert Mike Carlson will be putting each of the 32 NFL teams under the microscope, looking at their 2008 season and what the future holds. In this week's Coast to Coast column, Carlson looks at a San Diego Chargers team looking to reclaim their AFC West crown but improve on a .500 record.

The 2008 San Diego Chargers provided an object lesson in how we evaluate talent. They came into London last October a disappointing 3-4, yet in their 37-32 loss to the Saints on the slippery (hardly hallowed) turf at Wembley they showed signs of recovering their form. Yet after their bye they barely squeaked past the Chiefs, by a point, to go to 4-4. After losing three in a row: at Pittsburgh by a point, to Indy by three and Atlanta by six, they turned around and won their last four, three of them comfortably (again beating the Chiefs, at KC, by just one point).

The final win was a 54-21 rout of the Broncos that put them in the playoffs and cost Mike Shanahan his job. They then beat the Colts at home in the playoffs before losing to the Steelers to end the season 9-9. Going .500 was not what we expected.

9-9 smacks of Norv Turner, but if there were a lot criticism of Turner's performance in 2007, when he brought the team to the brink of the Super Bowl, there wasn't appreciably more as the team floundered. Much of that was due to Ed Hochuli costing them a win in Denver in week two, although they'd put themselves into position to lose that game.

What worried me, in London, was listening to the Chargers talk about what a good week of practice they'd had. Teams often say that, but the success of a Norv practice doesn't always seem to transfer itself onto the playing field on game day, and sure enough, against the Saints they were improved but hardly dominant.

The price was paid by defensive coordinator Ted Cottrell, who went back to Buffalo days with general manager AJ Smith; Cottrell seemed relatively unable to adjust as the season stumbled on, never really coping with the loss of Shawne Merriman or the relative ineffectiveness of Jamal Williams. This pointed the way to the lesson San Diego was teaching us.

Before last season the Chargers were thought to have one of the, if not the, deepest rosters in the NFL. And while that was a tribute of sorts to Smith, their season showed just how tenuous such distinctions can be.

One of Smith's hallmarks has been inordinate success with undrafted free agents. This allows him to sacrifice draft picks to move up and target specific players, but his success rate on such moves hasn't been as spectacular. Take the 2003 draft. Concentrating on rebuilding his secondary, Smith's top picks were Sammy Davis, Drayton Florence, and Terrance Kiel, none of whom will get into Canton without a ticket. His best pick that year was punter Mike Scifres in round five. But after the draft he signed Antonio Gates, Kris Dielman, and Kassim Osgood, Pro Bowlers all.

They are offensive players, but Smith has been especially willing to hoover up defensive players after the draft and coach their potential within the 3-4 defense. The problem was, when injuries were concentrated on his high-ticket players, the Chargers couldn't cope with their knock-on effects.

These were more clear-cut on defense, especially when Merriman was lost for the season in camp. Without Merriman's pass-rush threat, Shaun Phillips was less effective as a rusher, and neither Jyles Tucker or Marques Harris, both undrafted guys brought along within the system, who'd showed well in smaller roles, provided enough rush to compensate. Worse, Cottrell seemed oddly passive, something I've mentioned ever since he seemed to be scapegoated in New York, and went from being a hot head-coaching prospect to a long-shot for a job.

This time, his firing seemed more justified, as Ron Rivera immediately adopted a more aggressive approach: the Chargers needed to generate pass-rush through schemes, because teams weren't tilting their protection toward Merriman. Lingering knee injuries meant Jamal wasn't his usual force, (and the turf at Wembley seemed to affect him more than anyone) but at this stage of his career the Chargers have to expect Williams will wear down; undrafted Brandon McKinney regressed from a promising 2007, and eventually Ian Scott was brought in; Ryon Bingham is better-off playing the nose only in passing downs. With Williams less of a pocket-pusher, and no Merriman wreaking havoc outside, the lack of pass rush impacted the Charger secondary: the team ranked 31st in pass defense, and the injured Antonio Cromartie failed to come close to duplicating his 10 interception 2007.

ILB Stephen Cooper missed the first four games on steroid suspension, and Matt Wilhelm's apparent regression may owe a lot to not having Cooper to range alongside him. Derek Smith didn't have the range, Tim Dobbins is limited in coverage, but eventually took Wilhelm's job. Clinton Hart also regressed, partly the result of Eric Weddle's inexperience; Weddle is a playmaker but also gets caught out of position. Put all these factors together, and you can see why the team struggled defensively. This year they will again face a challenge, especially since defensive  line coach Wayne Nunnally went off to Denver, and end Igor Olshansky signed with Dallas.

Jacques Cesaire, undrafted out of Southern Connecticut, has been the third end, and offers a bit of pass-rush but is really pumped up at 295 and is much less run-stuffing than Olshansky, and I wouldn't be surprised to see Bingham outside on early downs. In best Charger fashion, the other candidates are undrafted small college guys who've been groomed for two years: you read about Keith Grennan (E. Washington) and Andre Coleman (Albany State) previously in C2C.

They signed Eric Bahktari out of USD last year as a LB, but he's apparently up to 285 and might well figure as a rusher. Inside, Smith used a fourth round pick on Vaughn Martin, out of Milford Academy via Western Ontario: he's huge, athletic, and raw, very much like Jamal when they got him in the supplemental draft. He might not be ready immediately, and might be tried at end as well, but if he develops he could be a great value replacement for Jamal.

They needed to consider a possible replacement for Merriman too, because even if he comes back at 100% he's in the last year of his contract. So Smith used his first-round pick on Larry English, an athletic end from Northern Illinois. English's production was questioned by some scouts, who noted he didn't dominate lesser college competition, but he has the kind of explosive burst on the corner that Tucker, for example, doesn't, and seems to be athletic enough to play in space at LB. Another last-year local signing, Antwan Applegate from SD State, probably gets his shot this year too.

Inside, they signed Kevin Burnett from Dallas, as if trading Olshansky for him, and he's penciled in alongside Cooper. Burnett never started inside in Dallas, and I've always thought him better suited to play 3-4. He's roughly the same size as Donnie Edwards, who worked inside for the Chargers, but you'd really like someone more like Wilhelm or Dobbins to take on blockers. Brandon Siler, a seventh round bargain in 07, may be ready to play more too. Watch for Dary Beckwith, who reminds me a lot of Siler; a player whose college production didn't hold up under the eye of pro scouts, but who might turn out to have some value. At 6-0 and 245 pounds, Beckwith's biggest flaw, bad instincts, is mitigated somewhat by the reduced space requirements of the 3-4.

Cromartie and Quentin Jammer on paper are one of the league's top corner pairings, and Antoine Cason, last year's first-rounder, makes it a strong trio on paper. You can see how much secondary performance relies on rush up front. Gordon will face a challenge from fifth-round pick Brandon Hughes, who's got more speed, but is basically a press-coverage man-to-man guy whose understanding of zone coverage is questionable. Undrafted Wopamo Osaisai, from Stanford, is a legit 4.3 sprinter who needs to learn secondary play; a raw version of Hughes. He replaces last year's undrafted DeJuan 'Trouble With' Tribble as the flawed speedster worth a year's coaching. They drafted USC's Kevin Ellison, sized like his linebacker brother Keith at 6-1 227 pounds, to challenge Hart, as an in-the-box safety. Weddle is the free safety, with supplemental draft pick Paul Oliver his backup, but CJ Spillman could prove to be their best undrafted bargain. He's decent range, can hit, and plays well on special teams. Steve Gregory, like Oliver was a college corner, and like Spillman, offers some special teams ability.

On special teams Scifres remains one of the best punters in the NFL, and why he didn't go to the Pro Bowl is beyond me. Nate Kaeding, perennial Nate-of-the-Week contender, was, according to Cockuppa below average as a kicker, and his effectiveness in the clutch is still not proven. Darren Sproles is a dynamic return man, though you'd like a backup option in case Sproles plays regularly at RB.

Offensively, the injury concerns were more subtle. LaDainian Tomlinson never seemed to be at 100%, though he threw a move at Wembley that was one of the best I've ever seen. Gates' ankle injury meant he never ran sharp patterns, merely drifted into spaces and used his size and hands to get the catches. Nick Hardwick missed the start of the season, which seemed to have a knock-on effect inside; Kris Dielman in particular was less effective than usual. Marcus McNeil hasn't played up to his rookie season, which may be down to the long-term effect of the back problems which caused his fall to round two, and RT Jeromy Clary didn't match his 2007 performance, after he'd replaced a similar late-round find, Shane Olivea. Now Mike Goff's gone, within the division to KC, and Kyle Forney, who didn't play last year, is expected to replace him.

Also gone is line coach Jack Henry, but his assistant Hal Hunter simply moves up to replace him. Hudson Hauck developed Hardwick (considered undersized) and Dielman (undrafted, and a college D lineman) and while after a year of Carl Mauck, Henry came in and had some success with McNeil, Olivea, and Clary, his departure may be one more of perception than playing reality.

In the draft they gave Hunter a couple of college guards to play with; third-rounder Louis Vasquez is a big mauler who ought to fit in, but faces some adjustment after playing in a two-point stance in Texas Tech's spread formations; Tech linemen have had trouble making the jump, but if Vasquez has learn to fire out, he could challenge Forney immediately. Round four's Tyronne Green, a short guard from Auburn was, like Dielman, originally a defensive lineman. Although he's short he can move and has a defensive lineman's arms and hands, so may figure as a center, and with the rest of the AFC West now playing 3-4, Hardwick's mobility is less of an advantage. Undrafted tackle Dan Gay has some potential, and scrappy center Ryan MacDonald may have reminded them a bit of Hardwick but would be ticketed for NFL Europe if it still existed.

Despite uncertainties up front, the injured Tomlinson still ran for 1,110 yards, but averaged only 3.8 per carry, and for the second straight year he bowed out hurt in the playoffs. Darren Sproles averaged 5.4 on his carries, which indicates there must've been some holes there, but can't be expected to carry the load, especially as you'd like to have him returning kicks as well. Tomlinson's problems seemed to stem from a lack of push off his injured foot; they suffered in short-yardage situations, and the original injury probably led to his later groin problems. They say he's back to 100%, but he's also 30, which has been a watershed mark for a majority of NFL runners.

Last year, Smith moved up to select Jacob Hester, a FB/RB tweener from LSU. Smith likes such guys, Andrew Pinnock, for example, and after a crucial fumble set Hester back early in the year, he ran pretty well at tailback. Now he's apparently bulked up from 225 to 240, which would indicate they see him more as a fullback this year. Hester was beaten out for the blocking fullback role by undrafted Mike Tolbert, a 5-9 245 bowling ball from Coastal Carolina; he's skilled but has problems on the second level. Interestingly, they've brought in Bill Rentmeester, one of Wisconsin's two blocking-first fullbacks, and there could be some competition for the job. When you think of Tomlinson's success behind the one-dimensional (but what a dimension) Lorenzo Neil, you wonder whether Smith wants multi-dimensional fullbacks because he'd like them integrated in the offense, or if he simply wants a tailback who can be a second fullback, saving a roster space and giving them more options.

At tailback, the third job - behind Tomlinson and Sproles - will be between Michael Bennett, who's got great speed but hasn't always translated that into running success, and fourth-round pick Gantrell Johnson, from Colorado State, a straight-line downhill runner with good power, who might turn into their short-yardage option if they don't feel Tomlinson or Hester are enough. Tomlinson will probably feature as a single-wing tailback too, as the Chargers jump on the 'wildcat' bandwagon; he can pass effectively and may enjoy reading holes in that formation. I'd love to say undrafted Curtis 'Boomah' Brinkley had a chance of making the roster, but he doesn't.

Receiver is another place where Smith has consistently favoured tweeners, although he traded for Chris Chambers and drafted Buster Davis in an effort to provide a quicker, better route-running threat. Norv's offenses are built on timing, but Smith's preferred big receivers, like Vince Jackson and Malcolm Floyd, are long-striders who sometimes find precision cuts difficult. Jackson, however, is coming off a breakout year where he's established himself as a difficult player to single-cover; with a healthy Gates, that means a problem. Osgood is a Pro Bowl special teamer, but wants a receiving role; on this roster he doesn't offer what they don't have: speed downfield, which is where David comes in. He's in danger of becoming a total bust, as injuries have derailed most of his first two seasons, but his talent demands he get another chance. Just to show teams often repeat failures as well as successes, in round seven they drafted another boom-or-bust type from LSU, Demetrius Byrd, who might spent the season on PUP after a car crash. Of course, round seven, rather than round one, is where those sort of picks should be made. Legedu Naanee is another of those TE/WR tweeners, a line going back at least to Josh Norman, and he played some QB at Boise St, which means more crazy options in the wildcat.

At tight end, of course, a fully healthy Gates is a weapon very difficult to defend. Brandon Manumaleuna is the blocking tight end, but not quite the force he was with the Rams. Kris Wilson came over from the Chiefs last year, but mostly played special teams. After the draft they signed Kory Sperry, Johnson's teammate at Colorado St, who's a receiving type tight end, tweener enough to line up as a wideout. For reasons best known to Smith himself, they also cut 6-7 Scott Chandler, from Iowa, and replaced him on the roster's fringe with 6-6 Tripp Chandler, from Georgia.

Philip Rivers is a quality passer; a strong leader who sometimes seems to let things gets the better of him, but you can't question his courage. He was the NFL's top-rated passer, 4,009 yards, 34 TDs, just 11 picks, 105.9 passer rating. Charlie Whitehurst was drafted as the backup of the future, but Billy Volek is adept at stepping in and keeping the offense working, which means by the time they have a role for Whitehurst he may be elsewhere.

The Chargers are the one constant in a division in flux: Oakland ought to be better, but the Broncos and Chiefs are both cleaning house and may struggle for a while, which leaves the division there for the taking. Smith's Chargers are a well-run team, but I think fall short of the prototype front-offices of our era: Colts (Bill Polian also comes from that Buffalo background), Ravens, Patriots, and Steelers. I say this because sometimes you feel Smith prefers coaches who will stick to his GM gameplan rather than being able to bring in a more dynamic coach and work with him to succeed.

But the Chargers have the tools for huge success. Norv needs to prove he's the workman who can use those tools, and Smith needs to show that all these nice tools actually fit into the jobs that need to be done. Offensive line, receiver, defensive end, linebacker, even safety are all potential strong points or potential weak points, and sometimes the team is just one sprain away from trouble.