Unlike offensive tackle, depth is pretty thin at offensive guard for the Detroit Lions. This may partly be by design considering four or five tackles will likely make the team this year, which in turn limits how many guards you can keep on the roster. In any case, the Lions will be in trouble if a starter goes down at this position, as there aren't really any solid backup options on the roster right now.
The two starters in 2012 will likely once again be Rob Sims and Stephen Peterman. Sims has performed quite well since joining the Lions in 2010, and he is returning as the starting left guard. Peterman has had his fair share of struggles in the past as the starting right guard, but he seemed to improve as 2011 went on. The thinking is he started playing better after the Lions added Leonard Davis during the season, as the extra competition pushed him to take his game to another level. Davis wasn't re-signed by the Lions this offseason, but hopefully it won't be necessary for the Lions to bring somebody in just to push Peterman this year.
Behind the two starters are Jacques McClendon, J.C. Oram and Rodney Austin. McClendon spent the first month of the 2011 season on the 53-man roster and the rest of the season on the practice squad, so his experience is quite limited. The same goes for Oram and Austin, who just joined the Lions a few months ago as undrafted free agents.
Given their lack of depth, the Lions' best options for backup guards are really players who primarily play other positions on the offensive line. Center Dylan Gandy, for example, can play guard as well, and somebody like offensive tackle Corey Hilliard could slide inside in a pinch. There was a lot of talk when he was drafted that Riley Reiff might begin his career as a guard, but for now the plan is to keep him at tackle.
Need going forward?
I'm sure the Lions would like to have more depth at guard, but there hasn't been much talk about them adding any new faces at the position. Perhaps there could be a situation like last year where the Lions add a guy like Davis to come in and push Peterman, but unless a starter goes down with an injury, it doesn't seem as though there will be any real changes made to this position this year.