Montreal Alouettes general manager Jim Popp says Michael Sam's football career hangs in the balance after his decision to abrubtly leave training camp on Friday for personal reasons.

Speaking to the Montreal Gazette, Popp refused to shed further light on Sam's departure but said a failure to return would spell the end of his football career.

“There’s nothing to tell you," Popp told the paper. "He wanted to go home, and that’s what he did. I don’t know why. When a guy wants to go home, they go home. He had some personal things to take care of. I wouldn’t be surprised if he returns. I’m surprised he left. I was very surprised.

"If he doesn’t come back, I would think football’s over for him. He’s the one that has to face that. But I don’t think he doesn’t want to play football. That’s why he came here.”

The defensive end has been put on the Alouettes' suspended list.

Sam, the first openly gay man to be drafted in the NFL roster, signed a two-year deal with the Alouettes last month.

The announcement of Sam's departure came on the eve of Montreal's exhibition opener against the Ottawa RedBlacks.The Alouettes won the game 26-9. 

"The Montreal Alouettes fully respect Michael Sam's decision and we rally around him to offer all the support needed. The team has left the door open and Michael is welcome to come back whenever he feels ready," the team said Friday.

Sam declared his homosexuality leading into the 2014 NFL Draft Combine. He was selected by the St. Louis Rams in the seventh round of the draft, but failed to make the roster. He later signed as a practice squad player with the Dallas Cowboys, but did not appear on their active roster during the 2014 season.

The SEC Defensive Player of the Year while at Missouri in his senior season, Sam appeared on Dancing with the Stars this past TV season and attempted to impress an NFL team by appearing at the veteran combine earlier this spring.

In four seasons with Missouri, Sam registered a 123 total tackles, of which 36 were for losses, and 21 total sacks. He also notched two interceptions.