He took the day off.

This game was the final regular season game for Alabama. Lewis went on to skip the bowl game in January in order to prepare for the NFL draft (he went to the Senior Bowl).

So, if it looked as though he wasn't hustling in this game...it was because he wasn't (likely in an effort to avoid injury).

FWIW...I also checked out Lewis' highlights against Arkansas mid-season where he was a much more active player.