The compressed weight scale of the Doncaster Mile is likely to sway Gai Waterhouse against running Excess Knowledge despite his win in the Prelude at Rosehill.

Waterhouse said she was mindful of his future and the Doncaster had lost its appeal, even though Excess Knowledge gets in with 50kg with dual winner Sacred Falls the 58kg topweight.

"The weights are too compressed," Waterhouse said.

"It doesn't give the rising stars like him any advantage.

"I remember about 20 years ago when I ran Gifted Poet who ran third to Skating and he carried 49-1/2 kilos and the top weight had about 63.

"This horse is only a kilo-and-a-half below a Group One winner."

Australian Cup winner Spillway has 51.5kg but will head to the Queen Elizabeth Stakes.

Excess Knowledge was sent out at $9 in Saturday's 1500m race with Leebaz the $2.50 favourite.

Leebaz assumed control mid-race with Excess Knowledge tracking him into the straight.

But Excess Knowledge had plenty in the tank and went on to beat Malice ($18) by a head, with Leebaz another three-quarters of a length away.

Waterhouse has not completely ruled out next Saturday's $3 million race, but said Excess Knowledge was more likely to run in the JRA Plate (2000m) two weeks later.

"We'll let the dust settle, but I'm mindful of his future and the spring," she said.

"I think he is a Melbourne Cup horse."

Excess Knowledge was one of a group of horses which had an interrupted journey from Randwick to Rosehill when the float carrying them broke down on the motorway.

Gold Coast visitor Rudy, who beat just one runner home in the Prelude was another.

Trainer Helen Page arrived in Sydney on Saturday morning and was in a car from the airport when she saw the breakdown.

"We were driving past and there was the float," she said.

"Luckily there was another one behind with some spare spots."

Page was pleased with the Villiers winner despite his eighth.

"He had to change course when he couldn't get a run and kept making ground."