If Frank backs down then maybe this was the motivation or C-Kel legit improved (probably some combo). If he does sit Kelly, then I don't know what the hell is going on, maybe it is pretty serious, but it could also just be Frank trying to control the expectations of the team. Maybe he is gambling here to get the team ready for CBE/KC.
Look I'm not saying this is some brilliant move, I'm just saying that Frank regularly does this and so far it seems like his head games have paid off.