And yet he's purposefully limiting the first team reps for both guys.
Look at it from this perspective: you have a huge game this week with a team you think is even better than the #6 ranked team that just beat you at home. So, do you get as many first team reps as possible for your freshman QB? Nope. You purposfully decrease his first team reps by splitting time with the other QB.
I don't think I'm going out on a limb here by saying that's not every coach's formula for success. Even if you think Bartels will play, for goodness' sake Muss, give Joe as much time with the first team offense as possible!