Greater Western Sydney's spluttering premiership bid has been dealt another blow with ruckman Shane Mumford in doubt for the Giants' semi-final.

A new day brought new worries for the one-time flag favourites, who are in danger of being without two of their best and fairest winners for next week's must-win clash against either West Coast or Port Adelaide.

Unlucky: The loss of Shane Mumford due to injury is a massive blow to GWS. Credit:AAP

Mumford was on crutches at Adelaide Airport on Friday to protect a troublesome ankle problem that has affected his form in recent weeks. The Giants said on Friday he would be assessed in the next day or two.

The hulking ruckman did not have a disposal in the first half and just three for the game against the Adelaide Crows, though he had 38 hit-outs and laid seven tackles in the 36-point defeat.