Chris Waller believes imported stayer Araaja is poised to break through for a first win in Australia as he launches a four-pronged assault on the Winter Racing Handicap at Randwick.

Sydney's premier trainer is confident after studying the mare's wet track form in France ahead of a 2000m test on what will be soft or heavy ground on Saturday.

Araaja was fifth in her first Australian start in the Anzac Day Cup (1800m) and then claimed the minor placing in a 2000m-benchmark race at Rosehill last month.

Both races were on good tracks, while three of her four career wins have been achieved on soft with one placing on heavy.

"I've had a quick look at her European form so that's a big plus," Waller said on his stable update.

"She looks well, and she's in very good form so she'll be hard to beat."

Araaja was the $2.70 favourite with the TAB on Thursday ahead of stablemate Vaucluse Bay at $4.40.

Waller is wary concerning Vaucluse Bay given the gelding struggled over the same trip at Randwick a year ago on heavy ground.

"You'd have have to question the track because he failed this time last year on a heavy 10 but he did bounce back and run second on a soft," Waller said.

There is also a question mark over former English stayer Solo Mission's prowess on a wet track given he is yet to run on heavy.

"He was a good first-up winner in Australia and then a touch disappointing," Waller said.

Solo Mission is third-up in Sydney after a fourth at Warwick Farm over 2200m on May 30.

Oklahoma Girl ($10) rounds out his runners and after six unplaced runs this preparation.