MONTREAL (AP) — Johnny Manziel was placed under the Canadian Football League's concussion protocol Wednesday.

The Montreal Alouettes quarterback was hit at the goal line last weekend, leading to a fumble that a teammate recovered for a touchdown in a 24-17 loss at Ottawa. Manziel completed the game, but missed practices Tuesday and Wednesday as the team prepares to play at Edmonton on Saturday night.

"On Tuesday morning, Johnny Manziel mentioned to our medical staff that he felt symptoms that could be associated with the prescribed medication he uses for a previously diagnosed medical condition," the Alouettes said in a statement. "He then missed practice in order to have some blood work done.

"In view of the hit he received on Saturday and the potential mitigating side effects of his prescribed medication, the Alouettes medical staff has placed Manziel under the CFL concussion protocol for further observation and precautionary reasons. Manziel will be closely observed and assessed in the next few days."

Manziel has said he suffers from bipolar disorder. The former Cleveland Browns player sought treatment for anger management and alcohol abuse as part of his acquittal on a 2016 charge of domestic violence and has vowed to stay clean to help get his football career back on track. He was cleared to play in the CFL with Hamilton, which trade him to Montreal on July 22 — after agreeing to undisclosed conditions.

The possible concussion is the latest in a string of injuries to Montreal quarterbacks that has already claimed Drew Willy, Jeff Mathews and Vernon Adams. Another quarterback, Matt Shiltz, recently returned from an injury but is not yet fit to start.

There was concern that Manziel had suffered a concussion during the game and should have been taken out, but coach Mike Sherman said he was looked at by experts and cleared to continue playing.

"I was right there when it happened," Sherman said. "He came off the field, sat down. We were going to go for two (on the convert) and then the doctor said he's out. Then we decided to go for one. I went over to the bench. He was talking coherently. It didn't look like there were any problems. The official came in right beside me. He said 'this is what I have to see.' So he came over and looked at Johnny and he said, 'Oh, he looks OK.' So that was that. There was a spotter and our doctors were there, so I left."

Sherman said he drove back from Ottawa with Manziel and all seemed fine. But Manziel missed practice while going for blood tests Tuesday and wasn't on the field again Wednesday, although he attended quarterbacks meetings both days.

"If I knew there was anything wrong with Johnny. . . I would never put a player in harm's way and neither would this organization," Sherman said. "The doctors looked at him. The spotter looked at him. He recited the playbook to us, which is not an easy thing to do. So at the point, he was ready to go in."

The Alouettes have banked heavily on Manziel to help save their season. The former Texas A&M star had a difficult CFL debut two weeks ago against Hamilton, throwing four interceptions in the first half, but looked much better against Ottawa.

Sherman said that if Manziel is able to practice Thursday there's a chance he could play against Edmonton, but that appears unlikely. Montreal is 1-7 this season and has won just once in 19 games going back a year.