Mickey Rourke -- 'Moneyball' is Frickin' TORTURE

Brad Pitt's "Moneyball" was 133 minutes of unbearable, brain-melting MISERY ... this according to Mickey Rourke.

Rourke was leaving the gym in L.A. yesterday when he joked about using the movie as a torture device ... "I'm gonna tie you to a chair and make you watch 'Moneyball' all f*cking night."

For the record, Rourke and Brad Pitt don't seem to have a beef ... in fact, there are all sorts of pics of them smiling together over the years. Guess he really just HATED the movie.

So, we gotta ask ...