1. Jyles Tucker -- Approximately 10 months ago, Tucker was on top of the world. He had recently signed a new five-year, $14 million contract and was getting ready to line up opposite Shaun Phillips as a starting outside linebacker. Now, less than a year later, he is in danger of falling out of the rotation entirely.
Because of the return of Shawne Merriman and the addition of Larry English, Tucker figures to be no better than the No. 4 outside 'backer in Ron Rivera's rotation. And, because of the emergence of second-year LB Antwan Applewhite, Tucker will have to fight for table scraps. The problem with Tucker is consistency; he has nine sacks in 19 career games, but five of those sacks came in two contests.
FS Paul Oliver
2. Paul Oliver -- San Diego thought enough of Oliver to make him the top pick in the 2007 supplemental draft, ponying up a fourth-round pick for his services. And after spending his rookie season glued to the inactive list, Oliver showed flashes of his true ability last year by carving out a key role in the dime defense.
Nonetheless, his spot in the rotation is in jeopardy thanks to the draft-day addition of SS Kevin Ellison. Ellison has an edge over Oliver because Ellison is a better in-the-box safety, allowing him to spell the oft ineffective Clinton Hart. That leaves Oliver to scrap with Steve Gregory, who also has an advantage due to his prowess on special teams.
3. Mike Tolbert -- Tolbert was a revelation early last season, adding a new element to the offense with his ability to catch the ball out of the backfield. He ran first-string the first 11 games of the season, but cooled down after a red-hot start (10 receptions in the first four games). An ankle injury eventually opened the door for Jacob Hester to take over as the starting fullback, a position Hester never relinquished.
Tolbert is in trouble if he can't win back his starting position. The backup fullback has virtually no role in San Diego's offense, especially with TEs Brandon Manumaleuna and Kris Wilson capable of playing the position. Additionally, with the Chargers toying with the idea of keeping four halfbacks -- LaDainian Tomlinson, Darren Sproles, Gartrell Johnson and Michael Bennett – there may not be roster space available for a backup fullback.
OT Corey Clark
4. Corey Clark -- The Chargers drafted Clark with an eye towards the 2010 season, as Marcus McNeill, Jeromey Clary and L.J. Shelton all have contracts that expire after the 2009 season. However, when it comes time to restructure the offensive tackle position after the season, Clark will still be an unknown commodity.
Norv Turner typically keeps eight offensive linemen active on game days. And barring injury, those eight will be McNeill, Kris Dielman, Nick Hardwick, Kynan Forney, Clary, Shelton, Scott Mruczkowski and Louis Vasquez. And with fourth-round pick Tyronne Green all but assured a roster spot, Clark may be relegated to the practice squad this year, which could severely stunt his professional development.
5. Charlie Whitehurst -- The Chargers never intended for Whitehurst to become their starting quarterback, seeing as he was drafted with Philip Rivers already on the roster. However, when a team spends a first-day pick on a QB, the hope is that he rises to at least the No. 2 spot on the depth chart. But with Whitehurst entering his contract year and backup Billy Volek under contract though the 2010 season, that seems unlikely to happen.
Whitehurst has shown flashes during preseason play, displaying a big arm and the ability to push the ball down the field. However, his decision-making and ability to protect the ball have been scrutinized. Whitehurst believes he can be a starter in the NFL and will likely leave after the season in pursuit of a legitimate shot at playing time; he has yet to attempt a regular-season pass in three years with the Chargers.
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Michael Lombardo is a member of the Pro Football Writers of America and a long-time contributor to the Scout.com network. His analysis has been published by the NFL Network, Fox Sports and MySpace Sports. He has followed the Chargers for more than 15 years and covered the team since 2003.