Found this on the supplemental draft:
The Supplemental Draft, is designed to allow underclassmen --who did not petition the league for early entry before the NFL Draft deadline but find themselves ineligible for the upcoming college season-- a vehicle for entering the NFL.
Don't know how he would be ineligible to return to college unless his academics aren't in order?
If he's not in school this semester, and I haven't seen anything to indicate that he is, then he likely wouldn't have enough hours to be eligible.
Like I said, I don't know, but all 5 of the guys seemed to believe that he will be eligible for the supplemental draft.