Definitely didn't seem fine with that skeletor esque weigh in.
Personally, I think It was the support of Ireland that made him pull that shit out of him. I think he had like 5000 people from ireland fly out. It was unheard of. I think that level of support / a whole country behind you can make you overcome some shit.
The main thing that effected his performance was likely just fighting a wrestler on 10 days notice when preparing for a striker. Regardless of what his camp says, I doubt he was doing much wrestling preparing for Aldo.
a knee injury Isn't gonna effect your striking that much, so long as It's stable and healed enough. More so jiu jitsu, wrestling and training In general.