If there's any doubt left about Mendenhall, it should be gone
This kid coming up big on MNF, responding when he's called upon, that's exactly what you want to see. He's going to make his mistakes now and then, cough it up at the wrong time, miss a blitz pickup here and there, but the more experience he gets the more you can see him just getting more and more confident. He's hitting the holes with authority, running downhill, falling forward, all the things you want to see a good RB do. Even with the slow start in the first half, he took the adjustments that the coaches made at half time and really kicked it into gear. The Broncos are/were #3 vs the run going into this game so having a big day on the ground is quite an accomplishment.
There will still be growing pains to deal with, you can be sure, this any doubt of whether or not this kid has it should be gone. All he needs is continued reps in game situations and he'll be scary good!