Undisciplined usually means not playing within the scheme against the run. He did all of his damage in the 2nd half when the Packers were not much of a threat to run the ball.
Regardless of performance, if coaches allow 1 player to abandon playing within the scheme, then they will eventually have complete defense doing the same thing and that would be a bad situation. That would basically be the Rob Ryan style of defense. Players often flashed great plays in his scheme but overall the lack of discipline killed them.
He played 19 snaps after not playing because of injury issues so it's not as if they are shutting him out in terms of playing time. His time will come.