Unbeaten mare Alassio faces the next phase of her gradual progression when she confronts an unfamiliar distance and track surface at Randwick.

The lightly raced four-year-old swill bid to extend her three-race winning streak when she steps up in distance for Saturday's SCG Trust Handicap (1400m).

It will also be the first time she has raced on a heavy track, unless the surface is upgraded before race day.

"I'm not confident with her in the conditions yet, though stepping up to 1400 won't be a worry for her," co-trainer Adrian Bott said.

"She's had a couple of runs and a trial in between. I'm not afraid of taking that next step for her. She relaxes well and she's got a lovely turn of foot."

A $50,000 yearling at the Inglis Easter sale, Alassio is finally repaying the patience of connections after taking time to develop at Tulloch Lodge.

She started her career at Kembla Grange in June last year and then had almost a year out before begining this campaign last month in Wyong.

"The owners have been very patient with her so it's great to see them getting rewarded," Bott said.

"It took her time to strengthen up. She wasn't overly big as a filly, but she's really filled out now.

"We've brought her along slowly and she's ultra-competitive wherever you put her."

Alassio was the $3.60 favourite with the TAB on Thursday ahead of the Kris Lees-trained Princess Posh at $4.60.

While Gai Waterhouse's training partner has no worries about Alassio handling this assignment, he thinks she is probably nearing the top of her range.

"Against her own age, sex and in the right race she could probably get away with it over a mile, but I can't see her sustaining her natural speed over anything further," Bott said.