I have formed the belief that he does exactly this. I can specifically remember the body part in three games I've seen him play this year, even blanking out on the second one last night.
Knee when Georgetown visited w/Cooley in January. Close to game's end.
Did not make a strong impression on me in the 1st UConn game.
Thumb against Villanova for certain.
Shoulder last night against UConn. Then later, something else I can't remember. This was after I'd already identified it as a thing he does.
In none of the instances was there a foul called nor was any announcer comment made until the camera focused on his self-massage, and then they remarked. Never a replay to show if something happened. And Carter went over to a ref after the shoulder 'incident.'
There are many things he does well, but I'm of increasing belief that these non-visible injuries, and the wincing & running in their aftermath are a dubious 'extra' that he adds to each game. My suspicions are raised, and I'll now watch more closely.