Matt Cassel will start again at quarterback for the Kansas City Chiefs on Sunday against Cincinnati. Coach Romel Crennel said Wednesday that quarterback Brady Quinn (concussion) has yet to be cleared by doctors to return. Quinn had told reporters earlier that he had the go-ahead to come back after sitting out the past two games. "He's feeling a lot better, doing a lot better," Crennel said of Quinn. "If he makes it through the week without incident, then he can be cleared for the weekend." If Quinn, who had started a game for the first time since 2009 before he suffered the head injury against Oakland last month, receives clearance later this week, Crennel said Quinn and Ricky Stanzi will vie for the backup role. The Chiefs are 1-8.