The Ravens have placed tight end Charlie Kolar (arm) and nickel cornerback Arthur Maulet (calf/knee) on injured reserve.
Kolar and Maulet will miss at least four games and will not be eligible to return until Week 18 against the Cleveland Browns.
Kolar broke his arm in Monday night's 30-23 victory over the Los Angeles Chargers, according to Head Coach John Harbaugh. He suffered the injury early in the fourth quarter but still finished the game, per the NFL Network's Tom Pelissero.
Kolar had not missed a game this season as a valuable blocker in the run game and a regular contributor on special teams. He also broke loose for a couple big plays, including a key 55-yard catch against the Bengals.
The Ravens have the NFL's deepest tight end group that includes Mark Andrews and Isaiah Likely, with Pro Bowl fullback Pat Ricard also a punishing blocker. However, Kolar's playing time has increased over the last four weeks, and he saw a season high 49.2% of the offensive snaps against the Chargers.
It has been a difficult season for Maulet, who has not practiced since Nov. 13 and has been limited to just three games due to injuries. He was one of the Ravens' top defensive players in summer practices but suffered a knee injury in training camp that required arthroscopic knee surgery and sidelined him for the first seven games.
In other roster moves, the Ravens did not activate nose tackle Michael Pierce (calf) from injured reserve ahead of Sunday's game against the Philadelphia Eagles. The Ravens have a bye in Week 14, giving Pierce an extra week to prepare for Week 15 against the New York Giants.
Linebacker William Kwenkeu and defensive end Chris Wormley were elevated from the practice squad for Sunday's game.
