And not just no-name scrubs ... we're talking some pretty famous NFLers who couldn't quite hack it with Vince McMahon's organization ... guys like Oakland Raiders legend Lyle Alzado.
Unclear why Alzado -- a maniac on the field -- didn't get a contract with the WWE (then WWF) ... but Hulk says he wasn't the only NFL star who didn't make the cut.
Hogan names names ... Bill Fralic (4-time Pro Bowler), John Matuszak (2-time Super Bowl champ) ... and explains that it takes a special sort of toughness to fake fight in the squared circle.
"You gotta be able to work hurt," Hogan says ... "You can't be taking a day off from wrestling because you twisted your pinkie if you're wrestling the main event at Madison Square Garden."
So, does Hogan think Sam has a shot?? Check out the clip ...
Fun Fact -- Matuszak went on to have a pretty decent career as an actor and famously played Sloth in "Goonies."