I've been think about this a lot lately. Right now Monty is seen as a WR playing RB, but could he be a full time RB? The biggest question is whether he can learn to make the right cuts on inside runs. If so, you'd have a RB who is really good at catching the ball out of the backfield. Not just one who can catch dump-offs and screens, but one who can run pass patterns.
If both Shields and Lacy are healthy enough to return later this year, the Packers will have to decide which one to activate. How Monty does between now and then could factor into the decision. A lot of people have been thinking that Shields has played his last game as a Packer. Could it be Lacy we won't see again?