Most of the scouting sites seem to agree that there are some questions surrounding Lewan.
FFtoolbox: The big concern though is his ability to seal the edge against fast pass-rushing specialists. His change of direction is seriously lacking and could be abused by doubles moves.
Walters: Even though Lewan steadily improved over the course of the 2012 season, he isn't quite a finished product. The junior could use more development before going pro. His run blocking is ahead of his pass protection. Lewan is reliable pass-blocker, but still needs work on his overall technique. He could stand to improve his quickness in getting depth in his drop. If Lewan is drafted at left tackle, he could always move to the right side if that proves to be a better fit for him, but if teams view him as a right tackle it will probably hurt his draft stock and push him lower.
CBS: Needs to stay focused to cut down on penalties and use proper footwork and technique, not simply relying on his natural ability. Struggled with jab-steps and counters back inside when battling South Carolina star pass rusher Jadeveon Clowney in the Outback Bowl, and didn't excel in high-profile matchups against Alabama and Ohio State earlier in 2012. Tends to drop his head upon contact.