It's been a revolving door for Miami, whose starter Arian Foster is out this week with a groin injury. Though he could return next week, it's no guarantee.
Either way, the Dolphins' running back situation has been a platform for coach Adam Gase to instill discipline on his team and establish a culture. That has led to different players being unavailable for different reasons.
The first week, it was second-year running back Jay Ajayi being left home from the trip to Seattle to send a message. He hadn't responded to coaching as Gase had wanted, and the hope was, leaving him back would be a wake-up call. He had a good week of practice and was back in the lineup in Week 2.
There was another situation that week, however. Running backs Damien Williams and Isaiah Pead missed a meeting prior to the game and were made inactive for the loss to the Patriots. Another message sent through discipline, one the players received loud and clear. Time will tell if there are any more corrections necessary.