GEELONG is set to wait until later in the week before deciding on Mitch Duncan's availability for Sunday's trip to Perth to play West Coast.

Duncan was a late withdrawal for the Easter Monday loss to the Hawks with hamstring tightness, the midfielder replaced by Nakia Cockatoo.

Jackson Thurlow was pulled out of the second half of the Cats' VFL season opener in Torquay, replacing Zac Smith on the emergencies list.

Thurlow wasn't required on Monday, but one other change was made, forward Esava Ratugolea replaced 20 minutes before the bounce with Irishman Mark O'Connor.

Meanwhile, second-year forward Sam Simpson is set to return to Geelong's main training group in the next fortnight after a knee injury.