I think the Tebow situation wouldn't compare to a gay player. The problems Tebow has faced has largely been because of his skillset and the media coverage. If Tebow was nothing more than a 4th year back-up QB in Denver, you wouldn't know he exists. He had good run with a coach/GM that didn't want him. He was traded to the biggest media market in the country. It's much less about his religious views, there have been plenty of holy rollers in the NFL, and more about the publicity. It's jealousy.
No one would be jealous of the gay guy. You'd have the faction in the locker room, like an Antonio Cromartie, who'd swear he was constantly looking at dude's dicks. Because, as we know, gay guys think about dick all day and would willingly suck any of them. Then you'd have the guys who'd agree with Cromartie but wouldn't say anything but "He's a good teammate." Then you'd have guys who think Cromartie is a goddam nutjob and wouldn't say anything but "He's a good teammate" because they think he is. Finally, you'd have the guy like Kluwe who'd go out of their way to "support" him. And it would be a media circus because everyone would want the story.