McKissic only got on the field last year because of the situation at RB. Carson was on IR, Prosise was on IR, and Davis was injured seemingly every other game....and the other guys just flat out sucked.
McKissic basically has no use to us as a RB now. He's terrible as an inside runner and is only useful as an outside runner if he gets a clean lane. He's a very, very bad pass blocker and being the WR convert that he is, his best and really only asset to us at RB is as a pass catcher.
Honestly, are you going to take Carson, Davis, or Penny off the field for a WR convert that is only good at catching the ball? He has no use case anymore except as a KR and MAYBE a gunner...unless he comes back as yet another small WR.
Even if you're talking Prosise, HE'S actually the healthy one now and we're talking about a "runner" in McKissic who's recovering from a broken bone in a running ass foot and was never good as an actual RB in the first place. McKissic played because of just how bad the situation was last year.
The situation's changed entirely.