The Kansas City Chiefs lost to the Baltimore Ravens, 9-6, on Sunday at Arrowhead Stadium, and that may not be the worst news. Chiefs quarterback Matt Cassel left the game in the fourth quarter after suffering what the team called a "head injury."

With 10:10 remaining in the game, Cassel dropped back to pass and dumped the ball off to running back Jamaal Charles. As he threw, the quarterback was hit by Baltimore defensive tackle Haloti Ngata and knocked to the turf. Cassell remained on the ground for a couple of minutes before being helped up. He left the field under his own power.

Brady Quinn came on in relief of the starter and completed 3 of 3 passes for 32 yards. Quinn was cheered by Kansas City fans, who have been clamoring for a change at quarterback.

Before his injury, Cassel struggled against the vaunted Baltimore defense. He completed 9 of 15 passes for 92 yards, and he was responsible for three turnovers -- two interceptions and a fumbled snap.