Kyle Boller's career as a Baltimore Ravens quarterback has taken several turns over the past five years, from first-round draft pick to oft-criticized starter to valued backup. Now, Boller appears to have a new role: late-game reliever. One day after Boller replaced starter Steve McNair in the fourth quarter against the Arizona Cardinals and led the Ravens to a winning field goal, Coach Brian Billick said he has no qualms turning to Boller in late-game situations as McNair continues to recover from a strained groin. There is no question McNair, who was injured in the season opener and missed the second game, is Baltimore's starting quarterback. But considering his age (34), the beating his body has taken over 13 NFL seasons, and the way Boller has performed this month, Billick said he would consider using a similar platoon even after McNair is healthy.