Former UFC champ Luke Rockhold is the latest fighter to say ... a big percentage of his colleagues secretly use steroids.
Luke was at Topgolf in Vegas when our photog asked about Jon Jones getting booted from the fight over a performance-enhancing substance. Luke clearly thinks Jon's a screwup, but doesn't think he's alone in what he did.
That said, Luke's clear the UFC is going after fighters who use these drugs like a rabid dog.
BTW ... he thinks Silva has a shot at beating Cormier in UFC 200, even with short notice. He has recent experience in that department.