If and when Bronny James needs advice on how to come back from a scary heart issue ... Ronny Turiaf, one of LeBron's old basketball pals, tells TMZ Sports he'll be there no questions asked for the teenager.
Turiaf, of course, famously underwent open heart surgery back in 2005 ... after docs found he had an enlarged aortic root. The procedure was terrifying -- it lasted hours ... and the former NBA player didn't know if he'd ever be able to hoop again even when he made it through it successfully.