John Thompson is confident missing a feature event last weekend with talented mare Peron can reap a Group race reward at Flemington on Saturday.

Peron was scratched from Sunday's Group One Sir Rupert Clarke Stakes (1400m) and will instead make her Melbourne debut in Saturday's Group Two Blazer Stakes (1410m).

"I just wasn't completely happy, you've got to be 100 per cent going into a Group One, but I've got to say pretty much as soon as we decided to scratch her she was doing super," Thompson said.

"I'm a lot more confident, she's a bit better placed this week on a bigger track and against mares."

A winner of six of her nine starts including the Listed Gai Waterhouse Classic during the winter, Peron will be second-up after a fast-finishing second to Driefontein in the Group Three Sheraco Stakes (1200m) at Rosehill first-up.

"She just took a little bit longer to settle in but she's great and worked super yesterday," Thompson said.

"She'll run well."

The trainer rates Peron as his leading spring hope in Melbourne with the Group One Myer Classic (1600m) a possible big-race target depending on how she performs in her next two starts.

"I'm not 100 per cent convinced she's a miler," Thompson said.

"I think she's more of a 1400-metre horse off a hot speed.

"Saturday's race and her next start in the Tristarc Stakes are both 1400 metres so we can decide after seeing how she goes in those races."

Nash Rawiller takes the ride on Saturday in a full field of 16.

The field also includes last-start Group winner Catkins, Group One winner Maybe Discreet, and last season's Kewney Stakes winner Flying Snitzel.

Thompson believes the trip away this spring could be the making of Peron who had her first eight starts in Queensland.

"This is the first time she's ever been off our farm in Queensland so I dare say this trip away will mature her in the head a little bit," he said.

"I still think she can win a good race this preparation, so to think she can improve again is a good thing."