The Oakland Raiders may be without defensive end Justin Tuck for a long period of time, possibly the rest of the season.

Tuck underwent an MRI for a chest injury this week and Raiders head coach Jack Del Rio said the results were "not good" at his weekly press conference Wednesday.

The NFL Network's Ian Rapoport reports that the team fears Tuck has torn his pectoral muscle and will miss many games and possibly the rest of the year.

The 32-year-old Tuck has 14 tackles and one sack through five games so far this season.

The Raiders are on their bye this week.