LeBron James Pissed About Dejounte Murray's Knee Injury, 'F*#% Man!'

LeBron James is straight-up PISSED that one of his NBA rivals lost a great player ... dropping an f-bomb when he learned Spurs baller Dejounte Murray was done for the season.

Murray's right knee buckled as he went up for a layup against the Rockets in San Antonio's preseason game Sunday ... and the team announced Monday he suffered a torn ACL.

Bron wasn't the least bit pleased to know one of his Western Conference rivals took that big of a blow, saying, "Man I feared that would be the case when I saw the play! F*#% man!"

In fact, the Lakers superstar made sure the 22-year-old knew he can lean on him if he needs him through the recovery process.

"You know how to reach me and where to find me if needed. Love lil bro!!"

As for Murray ... he was keeping his head up, writing on social media, "I Will Attack This Process Every Single Day And Use This Time To Become Even Sharper In All Aspects."

BTW ... Murray's still dating Jilly Anais ... which has gotta soften the blow at least A LITTLE bit, right??