The prospect of rain-affected ground in both Melbourne and Sydney has trainer Jason Warren optimistic about his chances in two states on Saturday.

Warren has French mare Suspicieuse and impressive last-start winner Longchamp Belle engaged at Moonee Valley while Loot `N' Run is one of the leading chances in Theraces.com.au Handicap (1600m) at Randwick.

Four-year-old Suspicieuse chases her first Australian win in the Dominant Handicap (1600m) while Longchamp Belle will be out to back up her last-start effort on a slow track when she runs in the Adapt Australia Handicap (1200m).

Moonee Valley was rated a slow (6) on Thursday which is fine by Warren.

"The wetter the better," Warren said.

"Both of them love it wet. The weather will not be an excuse."

Rain in Sydney on Thursday put Randwick into the heavy range which is no concern for Warren with Loot `n' Run who performs best on soft ground with six of his seven career wins coming on slow or heavy tracks.

"It's been raining up there (in Sydney) all morning so he looks well-placed on Saturday," Warren said.

Suspicieuse raced on-speed in her Australian debut at Sandown last month over 1600m, tiring late to finish fifth.

Warren was encouraged by the performance and said the mare had trained on well.

"I gave her a chance to get over that run and she's in good order," he said.

"Daniel (Stackhouse) might have went a bit early on her (at Sandown) and she just couldn't make such a long run, first-up from a spell."

Nine of her 10 starts have been on good rated tracks but Warren said the mare loves rain-affected ground.

Three-year-old filly Longchamp Belle has not raced for four weeks after winning at Flemington against her own age and sex over 1200m.

Warren wasn't completely happy with the filly's blood picture leading into another scheduled race at Flemington two weeks ago so he decided to wait for Saturday's Moonee Valley race.