ALAMEDA -- The Raiders are expected to place defensive end Justin Tuck on season-ending injured reserve with a torn right pectoral muscle, a source said on Thursday morning.

Tuck suffered the injury trying to tackle running back C.J. Anderson late in Sunday’s loss to the Denver Broncos. He tried to make an arm tackle from the ground, and his right arm got whipped back violently. 

Tuck will have surgery in the next few days to repair the damage.

The 32-year old was a key member of a strong defensive front and was a strong locker room presence on a young team. He is in the last year of a 2-year, $10 million contract. He will be a free agent at season’s end. It's possible he has played his last game in silver and black. 

Rookie second-round pick Mario Edward Jr. will replace Tuck in the starting lineup. Edwards has the skill set to fill in as a 3-4 end and an interior pass rusher on passing downs. Edwards is a strong run defender and is still developing as a pass rusher. 

Tuck has 66.5 career sacks, two Pro Bowl appearances and two Super Bowl rings from his time as a New York Giant.