Spencer Haywood Upset With Ja Morant, 'He's Ruining His Career'

Ja Morant might not care if he gets punished for his gun-themed celebrations ... but one former NBA great is pleading with the Memphis Grizzlies star to leave the safety on his controversial gesture -- telling TMZ Sports he's "ruining his career."

We spoke with Spencer Haywood out at LAX shortly after 25-year-old Morant was fined for his on-court antics ... and he had a strong message for the two-time All-Star and his inner circle.

"The people that are around him are not advising him right," Haywood said. "He's ruining his career, he's ruining his family's life, and his team most importantly, he's letting them all down. So, I'm just disappointed in Ja."

Haywood knows a thing or two about being among the NBA's best -- he was a four-time All-Star during his 12-year career and won a championship with the Los Angeles Lakers in 1980.

He added there’s "no excuse" for using the gun celebration when Morant has a history of being suspended for real firearms -- especially 'cause young kids look up to him.

Haywood -- who said he knows Morant personally -- is so passionate about it, he wants to address Ja directly about it all ... and mentioned he might be going to Memphis on behalf of the league to talk some sense into him.

Despite his strong stance, Haywood believes Morant can turn it around and put the drama behind him.