Oakland Raiders defensive end Justin Tuck could miss an extended period of time or even the rest of the season due to a torn pectoral muscle, according to NFL reporter Ian Rapoport.

Head coach Jack Del Rio declined to speculate about the length of time Tuck will miss due to the injury. Tuck's MRI result was, "not good," said Del Rio, according Zac Johnson of Pro Football Talk. The Raiders have a bye week this week, after losing to the Broncos this past Sunday, 16-10.

Safety Nate Allen used the team's only injured reserve/designated to return spot back in Week One when he tore his MCL against the Cincinnati Bengals.

Rookie defensive end Mario Edwards Jr., will likely fill the hole left by Tuck, and the second-round draft pick will likely have to make an impact if the Raiders want to contend this season. Edwards has eight combined tackles and a forced fumble, and even contributed on a sack against Peyton Manning last week. He played 50 snaps last week, and he is expected to have a larger role for the Raiders down the stretch of this season, according to Fox Sports.

Depending on the severity of the tear, an injury of this nature can take several months to heal. Will Beatty for the New York Giants tore his pectoral muscle back in May, and the doctors expected him to have a five to six month recovery period, according to Nick Powell of NJ Advance Media.

Tuck is a two-time Super Bowl winner with the New York Giants, and is a key part of the Raiders defense. The veteran pass rusher has 14 combined tackles this season with a sack, and will likely be missed, and Raiders fans are certainly hoping he can make it back this season.