“I couldn’t be happier with her as we speak but the forecast rain puts a question mark over her and a few of the others,” Newitt said.

“She’s OK on soft ground but what I don’t want is a track that starts off firm then gets cut out.”

Newitt said that Derasa encountered that exact scenario when resuming from a spell in Hobart 15 days ago and went “horrible.”

“The track was shifty underneath then started to cut out and she never went a yard in it,” the jockey said.

“She travelled good but when I let her head go there was nothing there.

“They had her blood tested and it was good and her work on Tuesday couldn’t have been any better so I’m very confident, except for the weather.”

Derasa hadn’t missed a place in Tasmania before her first-up failure and had been beaten less than half a length at two starts in Melbourne.

Online bookmaker Sportsbet opened the mare on the third line of betting at $6.50, behind I’m Wesley ($2.80) and Lord Da Vinci ($4.50).

Newitt expects I’m Wesley to be hard to beat.

“He’s also been working well and, although he’s got to give them a fair bit of weight, he’s earned it,” the jockey said.

I’m Wesley has 5kg more than when he won last year.

Newitt is chasing his second Newmarket win, having scored as a 16-year-old apprentice in 2001 on the Darrel Baldock-trained Chardere.

Exeter trainer Anthony Bullock will target all the feature races with consistent sprinter Posh Amber after her upset win in Tuesday’s Show Cup at Devonport.

The $13.90 chance began brilliantly from box 7 and led all the way to beat Stop Line ($1.50 fav) by 1-¼ lengths.

“I thought she’d be a chance if she led but I expected Stop Line to win,” Bullock said.

“She’s very quick and has gone close to the 340m track record in Hobart.”

Bullock said that Posh Amber, owned by Allan Clark, would have a crack at all the upcoming features, headed by the Hobart Thousand, Devonport Cup and Launceston Cup.

Posh Amber has 16 wins and 25 placings from 63 starts.