Currently the 29th rated Corner for the class of 2014, per nfldraftscout.com (CBS). That's not nearly good enough to be drafted. Their scouts must be posters here.
He'd have to skyrocket up the boards as a result of the combine. Could he do that? Not so sure.
Agreed Keon is not ready to be an NFL CB yet, he needs more time. If he goes now, he'll be undrafted and lucky to get signed as a UDFA and make a practice squad. The guy just is t ready right now. Keon just isn't one of the top 250-275 NFL ready football players in the NCAA. The only decision for him is to return.
As far as Jerome making a decision, it's at least plausible he could get drafted. I think he has late round potential, but his lack of athleticism and ability to break the big (aka long) runs and his lack of nose for the end zone, is very disconcerting to NFL scouts. That said, if you gotta have 3-4 yards, Jerome is your guy. That said if I were a betting man, very late round draft pick if at all, and again, just not ready.
Next year when he tears it up for 1300 plus, and another year of athleticism training, he could be a mid round pick with PTG.
All in all,they will both be back if HCDM is, and SHOULD be back even if he isn't. They have until the 15th to declare, and for their sake (and ours) I hope they come back.