The Montreal Alouettes' frustrating season took another big hit on Tuesday.

The Alouettes confirmed star quarterback Anthony Calvillo has sustained a concussion and will be unavailable for the team's upcoming tilt against the B.C. Lions.

Calvillo, 41, won't be suiting up Thursday for the 2-5 squad after he was drilled by Saskatchewan Roughriders defensive end Ricky Foley in a 24-21 Alouettes loss Saturday. He was injured on the first play of the second quarter and didn't return to the contest.

At the time of the injury, the Los Angeles native was 4-for-8 for 85 passing yards before giving way to backup Josh Neiswander. It hasn't been revealed when Calvillo will return to action.

The team did not confirm whether Neiswander, who struggled in Calvillo's absence in going 12-for-30 with two interceptions and 147 passing yards, will get the starting reigns against the Lions (5-2), according to CFL.ca.

It's the latest injury setback in what has been a disappointing campaign for a franchise with perennially high expectations.

Montreal has 12 players on the nine-game injured list and has already lost the likes of star running back Brandon Whitaker to a separated shoulder and two-time all-star receiver Jamel Richardson for the year with a torn lateral collateral ligament and anterior cruciate ligament in his left knee.

The team also struggled out of the gate and let go of new head coach Dan Hawkins just five games into his tenure, leaving general manager Jim Popp to take over on the sidelines.

Montreal also got some good news Tuesday, as it announced defensive end Anwar Stewart will make his season debut Thursday.