The Browns today placed linebacker D’Qwell Jackson on injured reserve with a shoulder injury he sustained in last Sunday’s game at Pittsburgh, the team announced. In addition, the club signed defensive lineman Keith Grennan to the practice squad and released defensive lineman Carlton Powell from the practice squad.

Jackson started all six games this season, and recorded a team-high 57 tackles, two passes defensed and one forced fumble.

“It’s disappointing any time you lose a player for the season, and this is especially true with someone like D’Qwell, who has proven to be an outstanding leader for us both on and off the field,” Eric Mangini said in a statement on Tuesday.

Grennan was originally signed to the Browns’ practice squad on September 9, before being released on October 9.