One of the key offensive components of the Stanford Cardinal team was injured early in Saturday's game against the USC Trojans.

Tight end Zach Ertz was forced to leave the game following the opening kickoff. It looks to be a knee injury. Ertz was seen on the bench icing his knee and is currently using a brace and crutches, Jon Wilner of the Mercury News reports. He is not expected to return to play in the game.

Ertz is one of quarterback Andrew Luck's favorite targets. He is third overall on the team in receptions, and fourth on the team in total yards.

Also apparently injured in the game was USC running back Marc Tyler, according to the official USC Trojans Twitter feed.There is no further news on this injury, but Tyler was seen heading to the USC locker room.

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