From the Mortensen chat on ESPN:
Oz (D.C.): Mort, what's the deal with Lavar and the Skins coaching staff? They say he's being benched fro practicing poorly but he says he doesn't get reps in practice! I find it hard to believe but is this punishment for his contract dispute?
Chris Mortensen: (11:14 AM ET ) I believe it's a bit of everything - contract, his unwillingness to play within the system, not attending one off-season workout (or so I heard), etc.