Major League Baseball just handed down a two-game ban on Aroldis Chapman ... after it says his meltdown on Monday night was simply "inappropriate."
If you missed it ... Chapman went off on Edwin Moscoso in the eighth inning of the Pirates' 6-3 loss to the Mets at Citi Field -- after he felt the home plate umpire had botched a few balls and strike calls.
Chapman walked off the mound toward Moscoso after giving up a go-ahead, two-run double .