If anyone thinks that Rafa is going to play pain-free for the rest of his career, or if he's played pain-free for even the past few years, you're kidding yourself. He'll tough it out, but I think his pain-free years are behind him.
Quite frankly I think Rafa has always had suffered some pain in his career,
Let us not forget he was diagnosed in 2005 with Muller-Weiss Syndrome, which is a debilitating foot condition, the doctors told him he may not be able to play tennis for too long, he has tried many treatments over the year, and finally found injections that helped him, in 2022.
His knee problems were always a concern, though he has managed them, apart from other parts of his body that got injured ( abs), I feel he has managed pain well over the years, and yes he has played tournaments when he shouldn't, he can be stubborn.