Sean Lee had 99 combined tackles with four interceptions and six passes defensed last season. (Jeff Gross/Getty Images)
Cowboys linebacker Sean Lee suffered an apparent leg injury during Tuesday's non-contact practice -- the Cowboys' first organized team activity of the season -- and was seen limping off the field with the help of two team officials, according to tweets from Calvin Watkins of ESPN Dallas.
The injury occurred when rookie offensive lineman Zach Martin blocked Lee during a screen pass. Lee was helped to the trainer's room and the extent of the injury is unknown.
The 27-year-old missed five games last season because of neck and hamstring issues, including the final three weeks of the season. He has missed a total of 18 games in his four-year career.