49ers depth chart 2014: What's next at tackle in free agency and the 2014 NFL Draft?

We've already taken a look at the depth chart along the interior of the offensive line and have a good idea of where the San Francisco 49ers stand in that regard. Namely, they're set at right guard, will need to address left guard before Mike Iupati's contract is up, and that the center position remains unsettled.

Now how about the offensive tackles? At first glance, it appears to be the most settled position on the team. Left tackle Joe Staley has really come into his own and is among the top left tackles in the NFL. More importantly, he's signed through the 2017 season. Anthony Davis is above average and still has room to grow, and his contract will keep him in San Francisco through the 2019 season.

As far as those two goes, there's not a whole lot to worry about. We did hear some reports recently that suggested the 49ers might be looking to re-do Staley's contract to get him some more money, which makes sense. He's out-playing his deal, and while we can't call him San Francisco's top priority this offseason, it is something to keep in mind going forward.

What's possibly been addressed this offseason is the swing tackle position. Generally, you want to enter a game situation with five starters and two solid, versatile backups: one who can play the interior and one on the outside. San Francisco typically uses an extra blocker several times a game, which is also worth noting.

The 49ers have employed Alex Boone as the swing tackle, and have typically moved Adam Snyder to Boone's spot at guard. But the 49ers have made one move this offseason that makes the entire situation interesting: trading for offensive tackle Jonathan Martin.

Nobody knows what the plans are for Martin. Some have suggested he's simply here to be the swing tackle, others have suggested that they could switch him to guard as insurance in the event that Mike Iupati is departing in free agency next season. I personally think it could be a combination of both.

Say Daniel Kilgore is the starting center -- I'd expect Martin to be the sixth offensive lineman on the field and for him to be the swing tackle, provided he hasn't regressed significantly and the he makes it through the offseason program without any issues. Whatever the case, Martin seems to clearly be the third offensive tackle on the roster and should be active on gamedays. I imagine Snyder will stick around as a backup guard, which is just fine by me.

At this point, I can't imagine the 49ers spending any top picks on tackles, obviously. I don't imagine they'll pick one up in any of the first four rounds, and I can't imagine a rookie being anything more than practice squad material at this point. Still, I'll go ahead and link out to the big board from NN user Poldarn, so you can take a look at the top-ranked tackles. They should also be about done in free agency, as well.