Michael Sam, newly signed defensive end for the Montreal Alouettes CFL football team, arrives on the field for rookie training camp in Sherbrooke, Quebec, May 27, 2015. 
Photo by Christinne Muschi/Reuters

Michael Sam stepping away from football

Updated

Michael Sam, who was the first openly gay player drafted by an NFL team in the league’s history, is leaving his Canadian Football League team, Sam and the team announced Friday.

“The last 12 months have been very difficult for me, to the point where I became concerned with my mental health,” Sam said in a series of Twitter posts. “Because of this I am going to step away from the game at this time.”

Sam was drafted by the St. Louis Rams last year but was later cut. He was signed by the Montreal Alouettes in May. The Alouettes announced Friday that the defensive end “has left the team for personal reasons.”

Sam made his debut with the Alouettes Aug. 7, but didn’t play much during the team’s 26-23 loss to the Ottawa Redblacks. Sam also left the team’s training camp last month for personal reasons, the team said.

In his college career, Sam was a star player with the University of Missouri and was named the 2013 Southeastern Conference defensive player of the year.

After he came out in February of 2014, the NFL said in a statement that “we admire Michael Sam’s honesty and courage.”

Sam became the first openly gay football player drafted by an NFL team when he was picked by the Rams in the seventh round. The selection raised hopes among some gay rights advocates that attitudes in professional sports have changed.

Rams head coach Jeff Fisher said the competition was fierce, and the decision to cut Sam was a purely “football decision.” After he was cut, Sam joined the Dallas Cowboys practice squad but was released by the team.

This story originally appeared on NBCNews.com

Michael Sam

Michael Sam stepping away from football

Updated