The travelling foreman for Irish trainer Aidan O'Brien is playing a waiting game with the final two of the stable's horses to arrive in Melbourne for the spring carnival.

TJ Comerford arrived in Melbourne in late September with a team of five including Caulfield Cup placegetter The Cliffsofmoher.

Stablemates Idaho and Rostropovich were on the final shipment of eight international horses to land on October 13 with the pair to finish quarantine on Saturday.

Comerford said there remained a possibility Rostropovich could run in Saturday's Cox Plate and take on Winx while Idaho may run in the Moonee Valley Cup.

"We've just got to see what Aidan wants to do," Comerford said.

"We'll find out during the week does Aidan want to run him (Rostropovich) in the Cox Plate.

"I've been on to him but Aidan will take whatever time it takes."

A decision whether Rostropovich lines up needs to be made by 8.30am on Tuesday.

Comerford says O'Brien wants to know the statistics of how many horses have competed in the Cox Plate and gone on to win the Melbourne Cup.

"He likes the horse and thinks he's a live chance, otherwise he wouldn't be here," Comerford said.

"I think there's been four in the last 11 years to run in a Cox Plate and then win the Melbourne Cup.

"They sound good and I'd like to think we could run in it, have a race out of it, and then see how we get on."

Comerford said if Rostropovich was to head to Moonee Valley then he would like to take Idaho away for a gallop.

"Or if there was something else for him, maybe he could have a run," Comerford said.

"Other than that we'd like to keep the horses together."