In reading an article earlier today on the 49ers offseason needs community poll, I was surprised to see offensive tackle so far down the list. While a position of need is usually one where either the starter isn't good, has left the team, or is aging and could soon be on the decline, none of these issues describe the 49ers' situation at OT. What is true, however, is that there are no solid backups at the position should one of the starters go down with injury.
Last season, the 49ers employed a strategy of assigning Leonard Davis and Alex Boone as utility players who could fill in at multiple positions on the offensive line. Davis was a backup OG and was likely expected to play some tackle (RT I would hope) if needed. Boone could slide over to LT or LG (where athleticism is more valuable compared to the right side) if there was an injury there.
While Boone began his career as a tackle, and I've always thought he had the potential to start there for some team if not the 49ers, he has now completed a full season at RG where he excelled. My gut tells me that the 49ers will want him to focus on his current position and not split his practice and study time keeping up with the OT positions as well. If he were a backup, I could maybe see him keeping the versatility in his repertoire, but something just tells me he's an offensive guard now.
Leonard Davis hasn't been re-signed and was an aging, generally unwanted player around the league anyway. He was a typical one-year signing for the 49ers, and perhaps they'll make another similar move this offseason. At any rate, if you look at the current roster, there isn't anyone at the OT spot to really back up the starters. Kenny Wiggins is a developmental guy who spent his 2012 season on the practice squad. He's also the only other non-starter with a "T" next to his name.
Cohesiveness can be a crucial factor for an offensive line; that is, spending as much time with the same five guys at the same positions as possible. For this reason, I think getting a solid backup at the OT spot makes the most sense at this point. Therefore, in the event of an injury, only one substitution would be made along the line rather than two, with Boone moving to tackle and a reserve OG replacing him.
Looking at the tackle position this way sheds some light on how big of a need it really is. Now, I wouldn't advocate spending a high draft pick on it, but you DO want to end up with a few guys in camp who could potentially see action in games if there was an injury. I'd say somewhere in the fifth round might be a good time to start looking.
Free agency may also produce someone who's got some experience at the position and would come cheap. The 49ers may decide to add a player in the draft AND FA, then let them compete for a roster spot/order on the depth chart. Still, I do think they'll add a tackle and I believe it needs to be a pretty decent one.