Speaks Out on Carl Nassib

Many have wondered if the roster decisions were more about Sam's sexual orientation than his skill on the football field.

In fact, in 2014 Sam told us straight up he believed he wasn't in the league because he's gay.

"I think I was the SEC Defensive Player of the Year last year," Sam said at the time ... "So I don't think it had to do with talent."

Now, Sam -- who retired from football in 2015 -- is praising Nassib for coming out publicly and also for his $100,000 donation to The Trevor Project.

FYI, The Trevor Project focuses on suicide prevention in the LGBTQ community.

"Carl Nassib thank you for owning your truth and especially your donation to the @TrevorProject," Sam said early Tuesday…