This is a bit tricky. Technically, the San Diego Chargers don't need an Offensive Tackle. They have a few signed through the 2013 season, including:
That's, uhhh, a lot of Tackles that are signed to the 2013 roster. That's actually probably more than you'd want on the active roster, but Schilling makes up for it by also being able to play Guard (I think, things change with Zone Blocking).
Clary has his haters, but he was the 38th best Tackle in the entire league in 2012 according to Pro Football Focus. He rated out at about average for his blocking skills across the board, but was the second best Tackle in the league at not creating/causing penalties.
Gaither is the key here. When Jared played, he played well and the offensive line was transformed by it. Mike McCoy and Tom Telesco could make the decision to try and repair the damage caused by Gaither's first season in San Diego, but most of the rumors coming out have the team either releasing the big Tackle or trying to find another way out of the contract they signed with him last offseason.
If staff is dead-set on immediately switching to a Zone Blocking scheme, Haslam and Harris would seemingly be good fits for it. Sounds like I have some work to do on a couple of "Cut Him or Keep Him?" polls for Gaither and Clary.
Now, as for the free agents. If the Chargers were to get rid of Gaither (and maybe Clary?), and if they weren't comfortable with starting Harris and Haslam, they would need at least one Tackle to come in and plug the hole. Who is out there?
- Jake Long, Miami Dolphins - Remember this? Well, that was back in the days of Norv Turner and Power Blocking schemes. If the Chargers were to sign a big-time free agent Tackle to a long-term deal this offseason, it would have to be someone they could build their Zone Blocking scheme around. That's probably not Jake Long. The Dolphins switched to ZBS in 2012, Long struggled and the team is content to let him go to team with a PBS.
- Brandon Albert, Kansas City Chiefs - Many Chiefs fans think that the team would rather let Dwayne Bowe leave via free agency than Albert, which means he'll probably get franchised. If he does not, he'd be a fine Tackle to come in and replace Jared Gaither as the team's Left Tackle.
- Ryan Harris, Houston Texans - Harris is mostly here for backup purposes. He started just 2 games last season for the Texans, and those are his only 2 starts since 2010. That being said, he was quite good as a backup and actually graded out better than Jake Long in 2012. He would provide the Chargers excellent depth at a tumultuous time.
- Winston Justice, Indianapolis Colts - Tom Telesco and Ryan Grigson brought the former Eagle to the Colts last year on a 1-year contract, and he performed well enough to justify his $1.5 million price tag. Is he a fit for Zone? Probably not. He'd be better suited for a team that could take a chance as him as a backup that can fight for a starting position without having to keep a guy like Gaither on the roster.
- Tyler Polumbus, Washington Redskins - He knows the Zone, but he's a terrible lineman and has been pretty terrible for a while.
See? Not much there if the Chiefs manage to retain Albert. If the Chargers want to replace their current Tackles with guys that aren't on the roster, their best bet is probably to sign someone like Ryan Harris as a backup plan for a high draft choice coming in to play Tackle.