Michael Sam should not have announced that he is gay because it's not worth mentioning. There are probably already a lot of homosexuals in the NFL, but they don't talk about it. Most people don't care who other people have sex with. He is just looking for attention by saying he's gay.
Michael Sam's admission that he is gay may hurt his draft status a little, but that is because it is unsettling to some people and some players. However, in the long run people are becoming more tolerant and know that a great player is what counts instead of what his sexual orientation is.
I believe there are still people out there with homophobic tendencies. Secondly, teams may want to avoid entering the next season with what could potentially turn into trouble in the locker room, if there are players on a team that are indeed homophobic. I believe he is far better off talking about it however, then letting it slide. We need people like Michael Sam to integrate into places like the NFL and prove that there is nothing to be homophobic about.
No, Michael Sam's admission that he is gay hurt his draft status, because if anything, it will help it. Coming out as gay is the politically correct thing to do. Sam's admission might have even been on purposes, because teams will now want to do the media-friendly thing and draft him for political purposes.
I don't follow sports, but from what I have heard on the news, he is one of the most likely people to get drafted into the NFL. I have heard some coaches anonymously tell the news channels that they didn't think that he would work out because of the homophobia in the NFL and the locker room, but I doubt that every team will pass up the opportunity to select this great player because of some speculation that it will be rough for players to adapt to a gay person playing with them.