The Chargers' 53-man roster is starting to come into focus. The injury to Ryan Mathews (broken clavicle) in the first preseason game against the Packers will impact who makes the final cut. Mathews is expected to be out four to six weeks. This will force coach Norv Turner to carry at least four RBs, which will limit his options elsewhere.

Projected 53-man roster

Note: Players listed in order of perceived depth.

QB -- In: (2) Philip Rivers and Charlie Whitehurst (free agent, Seahawks). Out: Jarrett Lee (undrafted, LSU) and Kevin O’Connell (free agent, Jets). Analysis: Lee is starting to show he could develop into a quality NFL QB, but the Chargers will likely try to sneak him on to the practice squad to free up the roster spot. O’Connell didn;t play in the preseason opener against the Packers and is expected to be off the roster when Whitehurst (sore, MCL) returns.

RB -- In: (4) Ryan Mathews, Curtis Brinkley, Ronnie Brown (free agent, Eagles) and Jackie Battle (free agent, Chiefs). Out: Michael Hayes (undrafted, Houston) and Edwin Baker (round seven, 250th overall pick). Analysis: Brinkley was considered to be on the bubble before the injury to Mathews but now could be the opening-day starter. Brown will likely remain the third-down back. Battle will provide depth as the third-string back and will contribute on special teams.

FB -- In: (2) Le’Ron McClain (free agent, Chiefs) and Jacob Hester. Out: No one. McClain, 6-0, 260, will supplant Hester, 5-11, 235, as the starting FB. They will also occasionally touch the ball as both a receiver and as an RB. Hester will primarily work on special teams.

WR -- In: (5) Malcom Floyd, Robert Meachem (free agent, Saints), Eddie Royal, Vincent Brown and WR-KR Richard Goodman. Out: WR-KR Micheal Spurlock (free agent, Buccaneers), Roscoe Parrish (free agent, Bills), Taylor Embree (undrafted, UCLA), Mike Willie (undrafted, Arizona State), Phillip Payne (undrafted, Nevada-Las Vegas) and Jason Barnes (undrafted, South Carolina). Analysis: Meachem is expected to be a starter, but Brown could claim the job if he continues to play well. Brown had four receptions for 81 yards and TD against Packers; Meachem didn't play. Royal will be the starting slot receiver. In question is whether Spurlock can claim the fifth spot from Goodman. Spurlock had two receptions for 52 yards against the Packers and Goodman didn't play. All of the undrafted free agents are likely competing for one or two practice-squad spots.

TE -- In: (3) Antonio Gates, Randy McMichael and Dante Rosario (free agent, Broncos). Out: Kory Sperry, Ladarius Green (round four, 110th overall pick) and Brad Taylor. Analysis: Gates is healthy for the first time in two years and could return to his Pro Bowl stature. McMichael will stay because of his blocking skills. The Chargers have concerns on the left side of the line and he can be used as an extra lineman. Rosario has shown he is a more complete TE than Sperry, who was the third-string TE last season. The Chargers would like to protect Green on the 53-man roster, but they may not be able to because the injury to Mathews requires the team to carry four RBs.

OL -- In (9): LTs Jared Gaither and Mike Harris (undrafted, UCLA), LGs Tyronne Green and Rex Hadnot (free agent, Cardinals), Cs Nick Hardwick and David Molk (round seven, 226th overall pick), RG Louis Vasquez and RTs Jeromey Clary and Mario Henderson (free agent, Raiders in 2010): Out: G-T Brandyn Dombrowski, Johnnie Troutman (round five, 149th overall pick), Anthony Davis (free agent, Destroyers of the UFL), Michael Toudouze (free agent Colts), Colin Baxter ,Cordell Bell (undrafted, Minnesota State-Mankato) and Phil Trautwein (undrafted, Florida) Analysis: Gaither (back spasms) has missed most of training camp. Coach Norv Turner has said Gaither will be ready to play by opening day, but that remains to be seen. Harris has seen the majority of first-team reps at LT, which will likely secure him a roster spot. Turner has already declared Green will be the opening-day starter at LG. Molk won the 2011 Rimington Trophy for best collegiate center and will likely replace Baxter as the backup center to Nick Hardwick. Louis Vasquez will remain the starter at RG, and Hadnot will back up both sides at G. Clary will retain his starting job at LT. Henderson will back up both sides at T. Davis and Toudouze were signed on Wednesday, and it's not clear if they will play LT or RT. Neither is expected make the roster, but they could make things interesting. Bell has played both sides at OT and is a strong candidate for the practice squad.

DL -- In (6): Left DEs Vaughn Martin and Kendall Reyes (round two, 49th overall pick), NTs Thomas and Aubrayo Franklin (free agent, Saints) and right DEs Corey Liuget and Antonio Garay. Out: Harrell Logan (undrafted, Fresno State), Damik Scafe, Charlie Bryant (undrafted, Memphis), Eddie Brown (undrafted, Texas A&M) and Garrett Brown (undrafted, Minnesota). Analysis: The Chargers are hoping Reyes will help collapse the pocket by providing more muscle up the middle. The entire group is expected to play a lot of reps this year.

OLB -- In (5): Shaun Phillips, Melvin Ingram (round one, 18th overall pick), Jarret Johnson (free agent, Ravens), Larry English, Antwan Barnes. Out: Darryl Gamble and Ricky Elmore (undrafted, Arizona). Analysis: The plan is to rotate this group in order to keep fresh legs on the field that consistently get after the QB.

ILB -- In (6): Right “MAC” ILBs Takeo Spikes, Jonas Mouton (round three, 2010) and Bront Bird and Left “MO” ILBs Donald Butler, Demorrio Williams and Andrew Gachkar. Out: No one. Analysis: Mouton is essentially a rookie because he missed all of last season after injuring his shoulder in the final preseason game. Butler had an outstanding year last season after missing his rookie campaign with a torn ACL. Williams will provide veteran depth and has looked good in camp. Bird and Gachkar are on the bubble and there may only be room for one.

CB -- In (4): right CBs Quentin Jammer and Marcus Gilchrist and left CBs Antoine Cason and Shareece Wright. Out: Greg Gatson (Arkansas), De’Andre Presley (Appalachian State), and Arthur Hobbs (undrafted, Nebraska at Kearney). Analysis: Jammer is coming off his worst season, which he attributes to a difficult divorce that led to bouts of depression. Cason is also coming off a down year in which he never seemed to gel with former DC Greg Manusky. Cason and current DC John Pagano appear to be working well together. Gilchrist will either be the starting nickel back in third-down situations or back up both corners. Wright and Gilchrist are competing for the nickelback job; the other will back up both sides. Gatson has been solid in camp and is a strong candidate for the practice squad.

SS -- In (2): Atari Bigby and Brandon Taylor (round three, 73rd overall pick). Out: Corey Lynch (free agent, Buccaneers). Analysis: Bigby will likely begin the season as the starter, but that is not set in stone. Lynch is on the bubble and has performed well.

FS -- In (2): Eric Weddle and Darrell Stuckey. Out: Sean Cattouse (undrafted, Cal). Analysis: Weddle has developed into a locker room leader. He had seven INTs last season -- tied for the league lead -- and he made his first Bro Bowl. Stuckey is a strong contributor on special teams.

Special teams -- In (3): K Nate Kaeding, P Mike Scifres and LS Mike Windt. Out. K Nick Novak, P Robert Malone (free agent, Lions) and LS Nick Guess (undrafted, Tennessee). Analysis: Novak missed a 35-yard field goal in the first preseason game. This was a big blow to his chances of keeping the kicking job over Kaeding, who tore his ACL in Week 1 last season. There is no perceived competition at either the punter or long-snapper positions.

Players on the bubble -- (8) QB Jarrett Lee, WR-KR Micheal Spurlock, WR Roscoe Parrish, TE Kory Sperry, TE Ladarius Green, OLB Bront Bird, ILB Andrew Gachkar and SS Corey Lynch.

Leading practice-squad candidates -- (8) QB Jarrett Lee, OLB Ricky Elmore, DE Harrell Logan, OT Cordell Bell, CB Greg Gatson, WR Mike Willie, RB Michael Hayes and TE Ladarius Green.

Likely to be placed on injured reserve -- (2): G-T Brandyn Dombrowski (foot, cyst) and G Johnnie Troutman (pectoral).

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