There is still a chance McNeill could agree to a long-term deal before the season begins. Unlike Vincent Jackson, who is in a similar spot, McNeill does not have a looming suspension or lingering character issues. However, if no long-term accord is reached, McNeill may sit the first 10 weeks of the season before reporting just in time to earn an accrued season.
While McNeill is out the Chargers will turn to 35-year-old Tra Thomas. A skilled pass protector, Thomas started just three games last year with the Jacksonville Jaguars. Prior to that, he started at least 15 games in 10 of 11 seasons with the Philadelphia Eagles. Thomas fits well in Norv Turner's pass-first offense, yet it remains to be seen if he can shake off the rust, or if he can do anything to lift a running game that ranked at the bottom of the league a year ago.
OT Jeromey Clary
The situation is much more stable on the interior line. Kris Dielman is arguably the top guard in the entire conference now that Alan Faneca has jumped to the NFC and Logan Mankins is stuck in a McNeill-like quagmire. Dielman is flanked by former Pro Bowler Nick Hardwick, who played well last season after missing 13 games with an ankle injury.
The player to watch may be Louis Vasquez, who impressed last season while earning the starting job as a rookie. Vasquez is a strong pass protector who can get downfield on screens, but he must do a better job of generating movement in the running game.
The Chargers have elite depth on the interior. Scott Mruczkowski, who started 13 games last year, is the top backup at guard and center. He is a strong, intelligent, proven commodity. Joining in the mix is second-year guard Tyronne Green, who excels with the pulls and combo blocks Turner asks of his offensive linemen.
The final player with a legitimate shot at making the active roster is Corey Clark, a seventh-round pick from the 2008 NFL Draft. Clark is a strong run blocker with the versatility to play tackle or guard, although he's admittedly more comfortable at the former position.
Prospects such as first-year center Ryan McDonald; rookie OG Jeff Hansen; and rookie OTs Brady Bond, Ryan Otterson and Nick Richmond will fight for roles on the practice squad. Early indications are that McDonald and Richmond have a leg-up in that competition, although the others will have much to say about it during camp.
What do you expect from the offensive line in '10? Discuss in the message boards.
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. You can see more of his updates by following him on twitter.