One of the smallest juvenile fields assembled this season is set to have the biggest bearing on Golden Slipper markets.

Three of the top four colts in Slipper betting - Headwater, Vancouver and Furnaces - will clash for the first time in the Group Two Todman Stakes (1200m) at Randwick on Saturday.

Headwater is the reigning favourite for the $3.5 million race but both Furnaces and Vancouver have held that mantle at different times.

Tommy Berry will partner unbeaten youngster Vancouver for Gai Waterhouse and he says the Todman Stakes will be a critical Golden Slipper form reference.

"There are three horses there who have been favourite for the Golden Slipper at one stage so it's going to be a great race," Berry said.

"Headwater, I've ridden in a trial and in a piece of work as well and he's the real deal.

"He's got everything you want in a two-year-old and he's the one to beat.

"But the thing with Vancouver is he's tough and I know he will be there at the end."

Vancouver was slated to oppose Headwater in the Silver Slipper two weeks ago but Waterhouse opted not to run him and the horse has since trialled strongly.

In his absence, Headwater vaulted into Golden Slipper favouritism with a commanding win in the lead-up race.

Trainer Michael Hawkes confirmed Headwater as a definite Todman starter and said the valuable colt was in "perfect" shape.

The two horses who filled the Silver Slipper placings behind him, Voiler and Mishani Honcho, round out the Todman field.

The fillies will stake their Golden Slipper claims in the Reisling Stakes with the Waterhouse-trained English an early favourite.

Like last week's Skyline Stakes winner Exosphere, English heads to Sydney after posting a dominant last-start win at Kembla Grange.