Australian Turf Club track manager Nevesh Ramdhani is predicting the Rosehill surface to tip into the heavy range with continuing rain forecast for Sydney.

Rosehill was rated a slow seven on Friday morning but Ramdhani expected it to be even wetter come race day.

"I think that's going to change given the way the rain has set in in Sydney," Ramdhani said.

"The Bureau (of Meteorology) is forecasting anything between 20 and 45 mils of rain.

"It's a little bit hard to determine exactly where we will be rated but I can tell you for sure it will be a heavy track tomorrow."

Ramdhani's prediction will throw a spanner in the works for punters with many horses racing at Rosehill on Saturday unexposed to a wet track for months.

But one horse almost certain to relish some cut in the ground is the Kris Lees-trained Stella Sea Sun.

The mare, who lines up in the NSW Bookmaker Co-operative Handicap (1350m), has raced four times on soft or heavy tracks for three wins and a second.

She showed she had returned in good order with a close fourth behind Aquitaine in December and is unbeaten second-up from a spell.

"It does look a good option for her," Lees said.

Lees will decide on race morning if European import Mugatoo makes his Australian debut in the Rosehill Bowling Club Handicap (1500m) but either way, the five-year-old looks a horse to watch.

A two-time winner over staying trips in England, Mugatoo made eye-catching ground in a recent barrier trial and has impressed Lees on the training track.

"He's a nice horse, lightly raced, and he appears to have a bit of upside," Lees said.

"We will learn more from Saturday. It's probably a bit short for him but he will be getting home strong.

"I'd probably prefer him on soft ground so if it's heavy we will just make a decision in the morning."

The rain has also been prolific south of Sydney with 32mm falling at Kembla Grange in the 24 hours to Friday afternoon.

The track was rated a heavy nine and with a forecast for further wet weather, officials will inspect the surface again on Saturday to determine if the meeting will proceed.