When the Detroit Lions drafted Riley Reiff in the first round last year, his versatility was seen as a big plus. During his rookie season, Reiff's versatility came in handy with him being used as a sixth offensive lineman. The Lions didn't have an opening at one of the five traditional starting spots on the offensive line, so they moved him around and used him like a tight end in order to get him on the field.
Reiff did start one game at left tackle in place of Jeff Backus, and he's expected to become a full-time starter in 2013. Where exactly he starts on the offensive line remains to be seen, though. Backus is considering retirement, so the left tackle job could open up. The right tackle job could also open up with Gosder Cherilus potentially departing when free agency opens. Reiff could fill either starting spot, and he could also be a candidate to take over for Stephen Peterman at right guard. According to Ian Rapoport, that might be the most likely option.
Interesting to hear how strongly #Lions are considering playing 2012 1st Riley Reiff at guard. Drafted as a tackle, so not great value-wise— Ian Rapoport (@RapSheet) March 5, 2013
While Reiff may have been drafted as the Lions' left tackle of the future, I don't see him playing at guard as a bad thing, mainly because I don't necessarily think it would be a permanent switch. If Backus returns, he will likely continue to be the starting left tackle. The right tackle job may be open, but Jason Fox has been mentioned as a candidate to take over for Cherilus. For 2013, perhaps having Reiff at right guard would simply give the Lions their best combination of starters.
Even if a move to guard did end up being permanent, it just means that you can cross that off the list of the Lions' needs going forward. The Lions will need somebody to take over for Backus at some point, but considering how the draft is shaping up, someone like Eric Fisher or Luke Joeckel could go No. 5 and be his eventual replacement.
Rapoport may view a possible move to guard as the Lions giving up on Reiff as a tackle, but I would simply see it as Detroit using Reiff's versatility to its advantage.