The retirement of Marvel Smith naturally brought a lot of consternation as to what the 49ers might do to shore up the now thin offensive line.  The team has their 5 starters, but there are big questions at the backup offensive tackle position.  Adam Snyder missed Saturday's game due to a knee injury, but is expected to be fine coming opening day.  However, he has yet to prove himself as a consistent force at the right tackle position, so depth is certainly a necessity.

The 49ers currently sit with Barry Sims and Alex Boone as their primary offensive tackle backups.  Beyond that they have guys like Jacob Bender, Joe Toledo and Matt Spanos.  A week ago they had no prayer of making the roster.  Today they've certainly got a chance, although I still don't see them making the roster.  I'd imagine we've heard all we need to hear about Barry Sims.  He's old and lost many steps in his game.  He was pretty atrocious last year, but one has to wonder how much of that was due to his aging and how much was due to the Martz offense.  Any thoughts on that?

The other man is of course fan favorite Alex Boone.  Boone has shown some skills and could very well end up being a player in this league.  One would imagine the retirement of Smith has come pretty close to locking up a spot on the roster for Boone.  Many would argue that it's way too soon to expect much out of him other than as an emergency fill-in.  I would tend to agree with that, although we all have heard his draft story.  He has talent and would have been drafted if not for his off the field problems.

No matter who you take from the above mentioned offensive tackles, I wouldn't exactly call it an awe-inspiring group at this point.  Certainly some upside, but a whole lot of "rough around the edges."

So where does that leave us?  Well, potentially in need of another offensive tackle.  Adam Caplan of Scout.com developed an updated list of best free agents still available on offense.  After the jump we break down some of the more intriguing options from that list.  We also utilize an older list from February.

Jon Runyan
This is definitely my favorite option at this point.  Runyan had microfracture surgery at the end of January, which was expected to keep him out four to six months.  Well, as of a few days ago, Runyan was cleared for full contact.  Back in February Caplan had an interesting comment about Runyan:

This mauling type of lineman is nearing the end of a solid 13-year career. Despite playing in a passing offense, Runyan actually may be a better fit for a team that uses a power running game.

Well, ya don't say?  Of course, before we get ahead of ourselves, both sides would have to want this to happen.  Runyan was drafted by the Oilers/Titans, but spent the majority of his career in Philly.  Would he be interesting in coming to the West Coast?  Adam Snyder is currently the starter at right tackle, but we know that's not a sure thing.  The team could ease Runyan back into things and if Snyder falters, Runyan could pounce on the job.  I'm not holding my breath for this to happen, but I am definitely intrigued by the possibility.

Mark Tauscher
The big problem for Tauscher is his recovery from ACL surgery.  There were reports that his knee was in pretty bad shape, but the last report I could find (end of July) indicated his rehab was running ahead of schedule, and he could be ready for game action in September.  Obviously take that with a grain of salt, but again, this is a guy the 49ers could ease back into the swing of things.

Charles Spencer
Spencer generally was considered a solid talent before going down with what sounds like a pretty nasty compound leg fracture.  He tried out for the Giants in May, but nothing ever came of that.  Spencer recently signed with the UFL so he's certainly looking to make a comeback.  As is the case with most everybody still available, plenty of injury baggage.  At one point he was going to be Houston's left tackle of the future, so the talent level was certainly there at one point.

Jason Fabini
Fabini is generally considered a serviceable backup at this point in his career who can play 3 positions (right tackle and I think both guard positions).  Of course, he's 35 years old so I wouldn't expect the 49ers would do much in terms of kicking the tires.

Levi Jones
The 49ers have denied interest in Jones, but I'll throw him on here anyways.  Jones is certainly talented, but it sounds like he wants a starting job and that won't happen at this point in San Francisco.

I refuse to list the two former 49ers that are on Caplan's list.

There are numerous other offensive tackles on their last legs that I certainly could have included.  For now though, I think this list includes the most pertinent options at the position.

In general, injuries are the overriding concern with any of the offensive tackles available.  I'm curious how one views knee injuries as compared to back injuries.  Do we have any old offensive linemen who would be able to provide us with some insight?  I ask because people might complain about bringing in another injured free agent tackle, but maybe a knee injury can be worked around a little more than a back injury.  Any thoughts?