Ben Bass to have MRI on shoulder

IRVING, Texas -- Dallas Cowboys defensive tackle Ben Bass will have an MRI on his left shoulder after getting hurt in Thursday’s practice. Bass could miss two weeks, but according to a source it could be closer to four.

Bass was limited in the session, and a potential absence would further hamper a defensive line that has taken more than its share of injuries.

Defensive end Anthony Spencer has not practiced since July 25 because of left knee surgery and suffered a minor setback over the weekend when his knee swelled after running. Defensive tackle Jay Ratliff is on the physically unable to perform list because of a sports hernia and will miss at least the first six games. Defensive end Tyrone Crawford was hurt in the first training camp practice, tearing his Achilles.

On Sept. 1 the Cowboys traded Sean Lissemore to San Diego.

If Bass’s injury is severe, the Cowboys would have only one backup defensive tackle in Landon Cohen behind Jason Hatcher and Nick Hayden.