Tyler Glasnow's Mom Scolds MLB Star For Cussing On Mound, 'Cover Your Mouth!'

"F***ing s***. Motherf***er. Every goddamn time. What the f***."

That's how Tyler Glasnow reacted when his teammate made an insane catch Wednesday ... and after TV cameras captured the whole thing, his mom was NOT HAPPY at all about it!!

The Rays pitcher's profane rant all went down in the 7th inning of Tampa's game against the A's ... when Kevin Kiermaier incredibly hauled in a fly ball DEEP in center field.

Glasnow was so PUMPED for the catch ... he spewed every swear word in the book -- and then tipped his cap to his outfielder.

The problem? Glasnow's words were so naughty AND so clear on the television broadcast, Tampa's ace said afterward his mom told him he needs to cut it out going forward!!

"My mom texted me like, 'You got to stop cussing on TV,'" Glasnow said. "'Like, cover your mouth or something!'"

Tyler, though, said he just couldn't help it!

"That’s my only reaction I can give him," Glasnow said. "It’s just unbelievable."

Don't worry ... Glasnow -- who by the way is becoming arguably the best pitcher in baseball -- said he will work on it, telling reporters after the game he's going to try to make Mom happy.

"There's some swear words going on when everything kind of goes well or someone does well," Glasnow said. "So, I should work on covering my mouth like my mom said."