I'm not going to assume things he's thinking, like you are. I've heard plenty of people, football people, who think Tebow, Manziel, and Vick can play. Tebow and Manziel are "winners", they lift their teams, they do the little things right. Dungy has said that. Vick obviously has the physical skills, and has been successful in the past. I haven't heard people say Michael Sam will be a good player in this league. He doesn't have the physical skills apparently. Some experts said he wouldn't get drafted, and it would have nothing to do with his sexuality.
Could he be a homophobe? Sure. I wouldn't assume that, though.