Carlos Boozer Gives Hair Advice to MLB Star

Carlos Boozer has a message for MLB star Carlos Beltran ... BACK AWAY FROM THE HAIR DYE ... saying Boozer's own hair horror story should be a cautionary tale for the Rangers star.

Beltran has been getting KILLED on social media for his new 'do ... which looks -- with all due respect, Carlos -- super damn weird ... like the man painted hair on a bald head.

It's not the first time we've seen it ... Carlos Boozer rocked the same style back in the day and was similarly roasted ... explaining later to Colin Cowherd it was a hairdresser's decision gone bad.

Check out the clip ... and Beltran, please, take the help.