The dilemma for the Chargers is that McNeill is coming off his worst season. The two sides nearly agreed to an extension before the season, but then McNeill injured his back and delivered his most inconsistent showing to date. He remained solid in pass protection, yielding a career-low three sacks, but struggled to generate movement in the running game.
Marcus McNeill gets beat by John Abraham.
McNeill believes injuries were a big part of the problem. He missed the first two games of the season and center Nick Hardwick missed the first three. Even after they returned, it took a while for the linemen to get back in sync.
"It's all five of us taking care of the line of scrimmage," McNeill said. "I was out early. Nick was out early. L.J. (Shelton) did a great job of filling in and Jeremy (Newberry) did a great job of filling in, but we also miss a lot of tempo and things like that."
The right side of the line houses the more pressing concern, as Jeromey Clary appears incapable of keeping up with the league's top speed rushers. Clary gave up 6.5 sacks during the regular season and four more during the playoffs, which is unacceptable for a team that relies on its passing game as much as San Diego.
The Chargers may look for an upgrade at right tackle in free agency, where the top options could include Khalif Barnes (Jacksonville Jaguars) and Vernon Carey (Miami Dolphins). San Diego could also wait until the draft, with first-round possibilities like Michael Oher (Ole Miss) and Jason Smith (Baylor).
Luckily, the Chargers already have good depth at the position. Top backup L.J. Shelton is a 10-year veteran who had started 57 consecutive games prior to joining the Chargers last season. He started San Diego's first two games last year in place of the injured McNeill and earned high marks from the coaching staff. He's especially valuable because of his ability to play left or right tackle with equal efficiency.
Like McNeill, Shelton enters the final year of his contract in 2009.
The fourth tackle on the depth chart is Corey Clark, a seventh-round pick out of Texas A&M in last year's draft. Although he was not active for any games, Clark stayed on the roster for 15 weeks, spending a one-week stint on the practice squad in Week 11.
Clark has a good build (6-foot-6, 312 pounds) and is a strong run blocker. He still needs to develop a mean streak and prove he has the lateral quickness to play on the edge, but the Chargers like the ability he has flashed thus far.
"In practice, every time I go out there I want to get better, so it's not like I ever feel content," Clark said. "I feel good with what I do but I always want more. I want to learn more every day and I want to get better every day."
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.