Updated

Johnny Manziel’s comeback attempt was put on hold Wednesday when his Canadian Football League team placed him in the concussion protocol after the ex-college star missed a second straight practice due to concussion-associated symptoms.

Manziel was tackled hard in the Montreal Alouettes’ game against the Ottawa Redblacks last weekend, the Canadian Press reported. Manziel told the Alouettes' medical staff Tuesday about the symptoms he was suffering from -- though he reportedly believed his condition may have resulted from taking prescription medication for bipolar disorder.

“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 Wednesday. “He then missed practice in order to have some blood work done."

The team added: “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.”

The Alouettes are set to take on the Edmonton Eskimos on Saturday. It’s unclear if Manziel will be cleared to play in that game.