Wingman David Mackay has withdrawn from Adelaide's squad of 25 to play Port Adelaide after failing to overcome a concussion.

Mackay was substituted at half time of Adelaide's clash with Essendon after an accidental kick to the head.

The dashing Crow has been replaced in the squad by young midfielder Mitch Grigg. Adelaide's team for Balfours Showdown XXXVII will be named on afc.com.au at 4:30pm on Friday.