Sage Rosenfels needs to warm up that arm. According to Fox Sports’ Jay Glazer, Matt Schaub will miss at least a month with an injured knee.

Texans quarterback Matt Schaub has a torn MCL and will likely miss at least a month if the team decides not to place him on injured reserve, multiple sources told FOXSports.com.

Schaub had an MRI Monday morning that confirmed the severity of the injury. The injury was sustained on a hit by Vikings Pro Bowl defensive end Jared Allen in the Texans’ 28-21 loss to Minnesota.

Sage Rosenfels will take over as Houston’s starting QB.

Schaub was having a pretty decent season. In the four games prior to the team’s loss to the Vikings, Schaub threw for an average of 308 yards and 2.3 TD. He missed five games last season due to a shoulder injury, so now one has to wonder if he’s simply an injury-prone player.

Fantasy owners should make a move for Sage Rosenfels. Despite a horrid fourth quarter against the Colts in Week 5, Rosenfels has played pretty well over the past couple of seasons in Schaub’s absence. In the eight games over the last two seasons that he has attempted 20+ passes, Rosenfels has thrown for an average of 220 yards and 1.9 TD. Not bad for a waiver wire pickup.