One of the best careers in NFL history is coming to an end in just two weeks ... Arizona Cardinals star J.J. Watt just revealed he's retiring following the end of this season.
The 3-time NFL Defensive Player of the Year made the surprising announcement on his social media page Tuesday morning ... saying he's grateful his two-month-old son, Koa, was able to watch his last-ever home game on Christmas.
"Koa's first-ever NFL game," Watt said in his announcement. "My last ever NFL home game.