Former Chicago Bears quarterback Jimmy Clausen, who played for Ravens offensive coordinator Marc Trestman last season in Chicago, was claimed off waivers by the Ravens to back up new starter Matt Schaub.
Quarterback Joe Flacco, who suffered a torn ACL and MCL in Sunday's win over the St. Louis Rams, was placed on season-ending injured reserve.
Clausen started once and appeared in four games under Trestman last year for the Bears, completing 54.2 percent of his passes with two touchdowns and an interception. He played twice this year, once starting in place of quarterback Jay Cutler, and completed 23 of 40 passes with an interception.
On Monday, Ravens coach John Harbaugh said experience in the Ravens' system that Trestman runs was one of the factors they would look at.
"I think that would be a plus, if we had that guy available," Harbaugh said. "Someone who has some experience would be a plus."
Clausen was waived Monday, with David Fales promoted from the practice squad to back up Cutler. The former second-round NFL draft pick in 2010 out of Notre Dame started 10 games for the Carolina Panthers that season, but has not been a full-time starter since.