Chris Waller is not sure if he can win the Caulfield Cup but he is certain it will reveal more about his chances in the Melbourne Cup.

Waller has the most runners of any Caulfield Cup trainer with four horses chasing the $3 million purse.

Three are last-start winners, each giving Waller a different angle to work with as he tries to lift the Caulfield Cup for the first time.

Junoob provides a Group One edge after his Metropolitan win, Moriarty goes in with a weight-for-age victory and Who Shot Thebarman has been impressive in Melbourne.

But only one is rated a serious chance at Flemington next month.

Who Shot Thebarman has crept his way into Caulfield Cup and Melbourne Cup reckoning but a moment of truth for the stayer has arrived after successive Flemington wins.

"Out of the race we need Who Shot Thebarman to be a genuine Melbourne Cup contender and therefore we want him to be finishing in the first three," Waller said.

Waller insists a lot has to fall into place for his horses to figure at Caulfield.

To some extent it already has with two overseas stayers ruled out because of lameness.

"You want to win it but you know how hard they are to win," Waller said.

"We've got to hope that others fail because we've prepared ours the best we can.

"You just need to have the horse right on the day, and as I said, hope some of those international horses struggle to acclimatise because we've got the home ground advantage."

Hawkspur completes Waller's quartet as the five-year-old returns to Caulfield after finishing midfield as favourite in last year's Cup.

Waller gave him a pass mark for a Turnbull Stakes run that didn't have much substance to it until the final 200m.