Another factor in getting granted a 6th year medical hardship is that you need to have lost two seasons due to "circumstances beyond your control". That does not include a typical redshirt. He obviously played a lot in '16 and '17 and it looks like in '15 he held for kicks so he appeared in every game that year. So he'd also have to contend that he was redshirted in 2014 due to "circumstances beyond his control" and not just because the coaches wanted to develop him.