I don't think a lot of people realize the player minutes is a zero sum game. In other words, the only way Conditt gets more minutes is for another player to get less. And we have a lot of good players.
Flip the question on it's head: what ISU player deserves to play fewer minutes?
There are also folks who hear "this guy should get minutes" and immediately turn it into 15-20min/game argument.
To answer your question, coach can "steal" 30-90 sec from any/all of his top 7 guys in order to get another player some minutes. You might do that just to help develop and provide experience for the kid. Or you might do it as a preventative reason to give your top 7 a physical break, mental break, limit foul trouble, situational offense/defense, etc.
Obviously Prohm is going to play who he trusts and earns it in practice. Sometimes I think he plays guys for too long extended minutes, which is often when lapses occur. I think a lot of coaches want to try to develop their bench, but few can ever find the perfect game situations to do it. If they go down swinging, they want it to be with their best players.
It can be a fine line. How do you win, while keeping your bench engaged and happy? Can you win while giving your bench game reps? Are you giving those guys enough reps to even show what they can do?