Take into account that players play hurt all the time. They even elect to put off needed surgery until it's convenient. It happens often.
He went out with the injury in week 7 and didn't return until he was "medically cleared" in week *16. Likely to meet his escalators, which would explain the 15 targets he received. He had 10 catches for 101 yards. I'd wager he received an injection before that game as well.
I have my own opinion on what happened, whether it's true or not. Antonio played hurt, returned for the good of the team and to reach his bonuses and wasn't happy with his involvement in the game plan. Knowing he would eventually need surgery on his ankle, he had that excuse in his back pocket whenever he needed it and here we are.