Say the Panthers decide that their cap problems are insurmountable and they decide to move on without Greg Hardy. Bad news: you would lose a talented player. Worse news: you would need to replace him with a DL capable of starting who is not currently on the roster. Better news: Hardy won't walk outright, but the Panthers will likely trade him, either straight up for a top 10 pick or more likely for a package of picks. And one one of those picks, they can replace Greg Hardy with ... Kelcy Quarles.
Yes, I know that I seem partial to South Carolina players, but it seems amazing to me that the Gamecocks don't recruit anywhere near the level of the top SEC powers and still wins 11 games a year. This year, the Gamecocks actually beat two teams that won big bowl games, Central Florida and Clemson. The Gamecocks have 4 juniors entering the draft and all of them but Clowney should be on the Panthers' draft board: Quarles, WR Andre Ellington, and 5'10" CB Victor Hampton.
Why Quarles? Because the Panthers in this scenario would be losing a pass-rushing DL that can stop the run, and Quarles is a pass-rushing DL that can stop the run. But Quarles is a DT, you say? Yes, a DT who had 9.5 sacks and 13.5 tackles for loss. How difficult could asking him to drop 15 lbs. and move to RDE be?
Yes, Quarles got a lot of those sacks because teams were doubling and tripling Clowney, but coexisting within a dominant front seven is what Hardy was doing anyway (please note that Hardy only got 7 sacks in his first 2 seasons when the talent on defense was lower, which is why the disastrous Frank Alexander acquisition was made).
But it is amazing that a 300 lb. DL from a top-ranked college program got 9.5 sacks, was named first team All-American and isn't listed among the top NFL prospects. Let's hope that he stays underrated and the Panthers are able to snag him with a 3rd round pick that they get in exchange for Clowney. Now again, teams draft college DEs and play them at OLB all the time. No reason to think that the Panthers can't draft a college under tackle and turn him into a RDE.