Owings Mills, Md. ? Baltimore Ravens rookie quarterback Kyle Boller probably will miss the rest of the season after injuring his left leg in Sunday night’s loss to the St. Louis Rams.

Boller tore his quadriceps just above the knee in the second quarter of the Ravens’ 33-22 defeat. The injury could require surgery, but even in a best-case scenario he would not be able to return until late December.

Ravens coach Brian Billick said Monday that Boller could be placed on injured reserve as soon as today. Chris Redman will start Sunday against the Miami Dolphins and Anthony Wright will move up the depth chart to No. 2.

Baltimore would sign a third quarterback this week, Billick said.

The injury occurred in the second quarter, either when Boller banged knees with Baltimore fullback Alan Ricard or upon being hit while rolling out toward the sideline.