I wonder why he would come back to college after one year in the NFL.
I would venture to say money. I'm sure the Giants job payed a lot better than what he was making at OSU, but money for assistants is not supposed to be an issue here.
Plus, he would be the offensive coordinator...he's currently a QB coach for the Giants. If he can do well as a coordinator, that's a launching pad to a HC job somewhere in a couple years.
Except that by all accounts, Riley calls his own plays.
He is a QB coach with the OC title and knows Riley's style of offense.