The Green Bay Packers confirmed Monday that left tackle Bryan Bulaga is out for the season with a torn ACL.
Bulaga was injured during practice on Saturday.
The team cancelled practice Monday and was not available for further comment.
Bulaga was moved from right tackle to the left side as part of the Packers' revamping of the line to better protect quarterback Aaron Rodgers, who was sacked a league-high 51 times last year.
Injuries have caused Bulaga to miss 11 games over the past two seasons. Losing Bulaga for the season would certainly be a big loss for the Packers.
The team had Sunday off as tests were taken on Bulaga's knee.
Last year's starting left tackle, Marshall Newhouse, could be moved back over from the right side or Don Barclay may shift to the left side.
Another option is to start rookie David Bakhtiari, whom the Packers drafted in the fourth round, at left tackle and keep Newhouse on the right side.
Also, former first round draft pick Vince Young was scheduled to try out for the team on Monday. He hopes to compete for a backup spot behind Rodgers.
Young has passed for 8,964 yards with 46 touchdowns and 51 interceptions over a six-year career with the Tennessee Titans and Philadelphia Eagles.
The Packers also have quarterbacks Graham Harrell and B.J. Coleman in camp.