Believe it or not, the NFL itself, IIRC, is treated as a non-profit for tax purposes. What it is, most accurately, is a crony capitalist cartel that restrains trade and economic competition. Socialistic, though, in more ways than you think.
As some have pointed out, Michael Sam probably should not be so happy about being a late draftee. He could be better off as a non-drafted player with the leverage to negotiate for his services with several teams and choose the best offer. Besides, the Rams, the only team he can negotiate with at present, are apparently strong at defensive line. But of course, socialists have no concept of free-market economics.
Which status could be reviewed and altered at anytime. I suspect that's why the NFL has gone so PC since Obama got into the White House.