The father of Missouri Tigers defensive end Michael Sam has expressed his displeasure at the news that his son is gay.

Sam, who made the revelation during a television interview on Sunday, would become the first openly gay player in NFL history if he is chosen in this year's Draft.

However, while the majority of reaction to the announcement has been positive, Michael Sam Snr admits that he is struggling to cope with the news having been informed via text a few days before his son went public.

"I couldn't eat no more, so I went to Applebee's to have drinks. I don't want my grandkids raised in that kind of environment. I'm old school. I'm a man-and-a-woman type of guy," Sam Snr told the New York Times.

"As a black man, we have so many hurdles to cross. This is just one he has to cross."

Sam Snr also said that Deacon Jones, a legendary Hall of Fame defensive end renowned for his hard play, would be "turning over in his grave" at the thought of an openly gay player in the NFL.

Sam is projected as a mid-round pick during May's Draft, despite leading the SEC in sacks and tackles for a loss on his way to being named SEC Defensive Player of the Year last season.