Dallas Cowboys linebacker Sean Lee could miss the 2014 season after tearing a ligament in his left knee in the first offseason practice.
The team hasn't announced results of an MRI but reported on its website Wednesday that Lee has been told he has a torn anterior cruciate ligament.
Lee went down during the 11-on-11 portion of Tuesday's practice. His left leg slid out from under him as rookie guard Zack Martin was closing in for a block, and Martin rolled over him.
The 27-year-old Lee hasn't played a full season in four years. The middle linebacker has missed 15 games over the past two years, including five of the final six games in 2013 with hamstring and neck injuries.