Schaub has missed the last three games with a left knee injury. He returned to practice last week and coach Gary Kubiak said he would consider playing Schaub against Jacksonville.
Rosenfels has completed 60 of 88 passes for 761 yards in Houston's last three games. He's thrown two touchdowns and seven interceptions.
Receiver Mike Walker was inactive for the Jaguars. Walker missed practice Friday, hours after a friend was fatally stabbed inside an Orlando nightclub.
Walker has 14 catches for 176 yards in six games this season.