Jimmy Butler's Shorts Stained During Mavericks Game, Fans Suspect Poo

All eyes were on Jimmy Butler's butt Wednesday night ... 'cause his shorts had a dark yellow stain on 'em -- leading many to believe he had crapped himself mid-game.

The unfortunate scene for the new Warriors star played out as he and Golden State were fighting to pull off a win vs. the Mavericks at the American Airlines Center in Dallas.

Eagle-eyed viewers of the tilt noticed that as Butler was making a drive to the lane with the Dubs down 109-107 late in the fourth quarter ... some unusual coloring had appeared on his white shorts.

When his tush was magnified by X users, it certainly seemed like Butler had had a bit of a bathroom accident.

Jimmy -- who was just traded to NorCal from the Heat earlier this month -- didn't seem too bothered by the situation if it was what everyone thought it was, he finished with 21 points, nine rebounds and seven assists.