I thought when tough-guy, Ohrnberger, was traded for and picked as a 4th rounder, he was actually selected to be converted to Center. Now Larsen seems to be a second possibility there. With his DT background, he is more aggressive than most C candidates. Wendell is the outside shot there, who was an UDFA and very undersized, too. But he stuck on the PS after a recommendation from a BB coaching confidant, and grown some.
All are potentially Guards too, but I don't think any are ideal there, with Ohrnberger the best of the center candidate lot, as a Guard.
The reserve Guards behind Mankins and Neal are Kaczur shifting from RT, and Connelly or Bussey, IMHO. Kaczur was projected as a G/T when drafted, and he became a starting tackle, on a 16-0 club, proving his ability. Bussey has the size, grittiness of a walk-on, and the talent to play LT, so he has the pass blocking ability seldom seen in a G. He could be a potential gem at G. Connelly has proved himself as a reserve. How he would do as a regular is a different question, still open.
I believe that there is a major transition due on the O-line in the next few years, perhaps hastened with the Mankins issue. Koppens is undersized, and gets pushed around by big NTs. The 3-4 is proliferating so there are more Big NT for him to face, too.
Neal is getting old and will play at most 2 more years, through his contract. At the critical LT, Light is aging very gracefully, but Volmer the heir-apparent, has already put in a claim, and will get some polish with a few years at RT.
I suspect that all though many will prove adequate players, the overall talent level will be augmented with a few high draft picks in the next couple of seasons, as well.
BB has just about completed re-uppolstering the entire Defense depth included, and made some progress in providing new receiving talent on Offense as well. So there are a plethora of draft picks that might be available to be used used there.