Adelaide full-forward Taylor Walker has been subbed out of the AFL match against Adelaide after suffering what appeared to be a serious injury to his left knee.

Walker had started the match at the MCG well, kicking the Crows’ opening goal.

But just minutes later he landed awkwardly in a marking contest and had to be assisted from the field by the Crows’ medical staff.

Within minutes Adelaide had activated their sub Rory Laird to replace Walker, who turned 23 on Anzac Day.