KANSAS CITY, Mo. (AP) - Chiefs quarterback Brady Quinn is being evaluated for what the team called a "head injury" after leaving in the first half of their game against Oakland on Sunday.
Quinn was starting in place of Matt Cassel, who was benched after a weak start to the year but entered the game when Quinn got hurt.
Quinn was hit hard on a sack by Rolando McClain on the Chiefs' third possession, and then took another shot when he threw an interception off his back foot.
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Cassel came into the game for the Chiefs' next series.
Cassel sustained a concussion three weeks ago against Baltimore and missed a game at Tampa Bay before getting benched. He was cleared to practice during the Chiefs' bye last week.
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