Ciaron Maher wants more rain in a bid to help Azkadellia's chances of upsetting Winx in the $3 million Doncaster Mile.

Azkadellia is one of five horses on the minimum 50kg in a race regarded as Australia's premier event for sprinter-milers.

In a market dominated by crowd favourite Winx, Azkadellia shares the third line of betting at $11 with Happy Clapper.

Winx has a stranglehold on favouritism as a $1.85 chance with her stablemate Kermadec on the next line at $6.

Randwick has had almost 160mm of rain during the past week, forcing a track downgrade to heavy before acceptance time on Wednesday.

But with better weather approaching the first day of The Championships, officials are confident the track will improve to the soft range on Saturday.

Maher is hoping the forecast is wrong because a rain-affected track will help Azkadellia while making Winx's task more difficult as she gives his mare 6.5kg.

"Usually with a weight difference on an affected track it can bring (the lightweights) into play a bit more," Maher said.

"She's got a good weight pull on the favourite and she'll need every bit of it.

"She will probably want a bit more give in the track but she's run well on top of the ground, so whatever it throws up, it throws up."

With the prospect of some rain-affected going, Maher expects Azkadellia's draw of 12 in a 15-horse field to be an advantage because the mare prefers to have galloping room.

After winning over 1400m at Caulfield last month, Azkadellia made her Sydney debut with a half-length second to Peeping in the Coolmore Classic at Rosehill on March 12.

The four-year-old has stayed in Sydney and Maher reported the mare worked well on Tuesday morning.

Azkadellia has the bonus of having five-time Doncaster winning rider Glen Boss in the saddle.

Boss first won the Doncaster in 2004 on the John O'Shea-trained Private Steer and is chasing back-to-back wins after landing the prize on Kermadec last year.

"He chased the ride," Maher said.

"With no weight and being in good form, she's obviously a good chance."