Former Pittsburgh Steelers running back Jerome Bettis has backed Missouri Tigers defensive end Michael Sam's decision to come out ahead of the 2014 NFL Draft.

Sam is expected to become the first openly gay player in NFL history when the May Draft takes place, with many projections putting him down as a mid-round pick.

"For him to make it public that he is gay, the key word is he knows who he is and he's comfortable with who he is. I think that sends the message that it is okay and I think that's what everyone needs to take from that. It is OK that he is gay and wants to play football in the NFL," Bettis told ESPN.

"I think this is the perfect opportunity for the NFL to now make this a point to communicate to every NFL team now you have to understand, now you have to bring these players to this moment.

"You're always going to have one or two guys that feel strongly in a different capacity but that's going to be in any situation you deal with. You understand that and hope those players allow him to be in that locker room and give him the respect he deserves being in the locker room."

The NFL have already released a statement expressing their support for Sam.