The first situation that comes to mind is Larry Bird. The Celtics played the hell out of him and Kevin McHale because they simply had nobody else to go to. The worst casualty of it was Bird who began developing back problems when most players were just hitting their prime playing years. By the time a normal player would have been starting the decline of skills (early 30s) he was coming out of games and lying on the floor courtside while the trainers tried to work the knots and agony out of his back. His career ended even though the Celtics had planned to sign him to another 5 year contract. His body simply couldn’t take the constant pounding. On a similar note, Bob Cousy wrote in his book about teams running players into the ground in order to win at all costs. He mentions one in particular (he doesn’t mention a name but makes it pretty clear through the details that it was WIlt Chamberlain) who played the first 3 quarters of a playoff game and then came limping off the court. They took the player to the locker room and discovered his shin was broken. His sock was full of blood and the bone was protruding through the skin just above the ankle. They doped him up with morphine, reset the shin as best they could, taped him, shot cortisone into his leg and then sprayed that old ice in a can on it. He came back on the court with 7 minutes left and played the rest of that game and almost the entire next game in that condition before the series ended and the player could receive proper medical treatment. It was that book that resulted in the field of sports medicine being created.

I’m sure additional research would yield more specific data and names and maybe some of the other guys know of specifics off the top of their heads. Wasn’t there also a player that had a heart attack during a preseason game? Or maybe it was college. It was a couple of years after the Len Bias tragedy and got a lot of ink at the time.