Mike Tyson's health scare in May has some fight fans worried about his chances against Jake Paul next month ... but that group doesn't include combat sports legend Quinton "Rampage" Jackson, who tells TMZ Sports he's still rockin' with the former heavyweight champ!
We recently caught up with the retired UFC superstar at LAX ... and asked for his thoughts on the November 15 mega fight between 58-year-old Tyson and 27-year-old Paul.
Even after dealing with the ulcer flare-up that caused the fight to be rescheduled (from summer to Nov. 15), Jackson tells us he'd never bet against Mike!
"He's my favorite boxer," Rampage said.
While he acknowledged "Father Time is undefeated" ... that won't deter Jackson from rockin' with one of the GOATs against his much younger opp.
"Anything can happen in the boxing ring," he said. "But I ain't gonna go against Mike Tyson."
We also asked Rampage about Tyson's comments made during an appearance on "Jimmy Kimmel Live," where Iron Mike said there's a possibility he'll be fighting while high ... and he isn't taking it all that seriously.
"I don't know about that," Jackson said. "Mike Tyson is probably just talking s***, man."
Whether Tyson was genuine or not ... Rampage says he doesn't believe fighters should smoke weed before competing, believing it can only hurt, not help.
Bottom line -- Quinton believes Tyson will have enough in the tank, high or not, to "shut that kid up."