ADELAIDE spearhead Taylor Walker has suffered a nastly-looking knee injury early in the Crows' match against Carlton at the MCG.

Midway through the first quarter, Walker landed awkwardly on his right leg after attempting to contest an aerial duel.

The big Crow hyperextended his knee and was taken from the field.

However, Fox Sports' commentator David King said the Adelaide doctors had initially diagnosed the injury as a "significant strain" but not a ruptured anterior cruciate ligament.

He was substituted out of the game, and replaced by Rory Laird.

Walker, who turned 23 on Thursday, had started the game strongly, taking several marks and kicking 1.1.