Rafael Nadal -- one of the greatest and most successful tennis players to ever pick up a racket -- just announced he's walking away from the sport ... with his last match slated for November.
The 38-year-old Spanish superstar broke the news in a heartfelt social media post on Thursday ... saying the decision has been a long time coming, especially with how the past two years have played out for him.
"I don’t think I have been able to play without limitations," Nadal said.