..it's never been the medical staff's call on whom to play, we can all agreed.

It's clear Rose was cleared to play. With a Lizfrank injury, and if he was "barely able to walk," I doubt any medical professional is going to clear him to go back in. Even so, if he's "barely able to walk," I doubt this thought goes through Whittingham's head:

"Oh, Isaac started nearly every other game and I went this guy Rose, and now Rose is 'barely able to walk.' Rose it is!"

What I think is more likely going on is that he was cleared to play in the 1st half because he didn't have that injury until much later. And he could walk just fine. And Whittingham kept him in because he saw no reason from a current AND FUTURE standpoint to take him out.