The Montreal Alouettes will have to start the 2012 season without their top defensive lineman.

The CFL club announced Tuesday that rush end John Bowman, who had a team-high 12 sacks last season, is out four to six weeks after suffering a knee injury during training camp Saturday.

The six-foot-three, 255-pound Bowman was hurt taking part in a short-yardage situation and was taken off the field on a cart.

With the 29-year-old Bowman out, the Alouettes would appear to be in the market for a defensive lineman and that could open the door for the potential return of veteran defensive end Anwar Stewart.

Stewart played 10 seasons with Montreal, helping the team win Grey Cup titles in 2009 and '10, before being released this off-season.

Stewart has yet to sign with another CFL team