Flemington trainer Simon Zahra is keeping an anxious eye on the weather as he plans Whistle Baby's next start.

Zahra, who trains in partnership with his cousin Mathew Ellerton, said their preferred option was 1200m-race at Swan Hill on Friday over a 1400m-race on her doorstep the following day.

But with rain predicted in north-western Victoria coupled with the mare's dislike for wet tracks, the $100,000 Golden Topaz at Swan Hill seems less and less likely.

"The weather is going to tell us where we're going," Zahra said.

"I would more than likely say Flemington, but we'd love to go to Swan Hill as it looks like a good race for her."

Zahra has ruled out accepting with Whistle Baby in both races and will talk to connections after he gets a better idea of the likely track condition at Swan Hill before making a decision.

The Flemington race is the third heat of the VRC-CRV Winter Championship.

Whistle Baby has been in work for nine months and will be having her 10th run this campaign, but with winter here the mare's next run will probably be her last.

"As the tracks have been pretty good lately and she hasn't trained off we've been happy to keep her in work, but this one might just see her out," he said.

Whistle Baby has been a consistent performer since scoring first-up at Moonee Valley last November and is coming off a last-start second over 1200m at Flemington on May 21.

Her previous seven runs had all been over 1400m, resulting in three minor placings.

"We went back to the 1200 (metres) the other day and she wasn't far off," Zahra said.

"She's been pulling a bit in her races at 1400 and hasn't quite been finishing them off.

"We're not worried about the 1400 but it looks like a strong race."