Merion failed to get the Group One win Mike Moroney hoped he might in the spring but the trainer has high hopes for his next campaign.

Three-year-old Merion kicks off his preparation towards the Australian Guineas in a strong William Hill Plate (1300m) against his own age on Saturday at Sandown.

Merion won a Listed race second-up in September but finished sixth in the Group One Caulfield Guineas a month later, less than four lengths behind the winner Shooting To Win.

Merion drew well in the Guineas but raced intractably which Moroney said cost him any chance of victory.

"He was probably going to be in a winning position in the race too, so that was disappointing," Moroney said.

"He still ran terrific because he locked his jaw and ran off the whole way, was the widest runner turning for home and still ran home.

"We aimed him at the Caulfield Guineas so it was disappointing to miss out."

Moroney says Merion is forward enough after two jump-outs but believes he will have to go back from an awkward draw.

The trainer will decide after the Australian Guineas whether Merion steps up in distance beyond 1600m.

Merion is at $10 for Saturday's race with the promising Onerous $3.20 favourite.

Unbeaten Godolphin colt Hauraki is at $3.70 ahead of Profit Share ($4.80) and Chivalry ($5) who won the McNeil Stakes first-up last campaign.

Onerous won easily on debut in August at Bendigo before finishing midfield in the Group Two Danehill Stakes.

He resumed with a three-length win at Seymour in what jockey Dwayne Dunn said was a confidence-building exercise for the talented colt.

"This should be a nice progression forward," Dunn said.

"It was a good win first-up. We tried to get him a bit of confidence, which it did, and hopefully he can take the next step," Dunn said.