James McDonald is already locked in for one of the best mounts of the autumn but it now seems every leading trainer has the young jockey on their carnival wish-list.

After winning doubles at the past three Sydney metropolitan meetings, demand for his services has never been higher for the New Zealand rider who has risen to fame in Australia on the back of It's A Dundeel.

The 22-year-old is tipped to continue his run of sparkling form with an outstanding book, including three pre-post favourites, at Rosehill on Saturday.

And he is already in the box seat to extend his winning spree to Melbourne next week when he rides at the Blue Diamond Stakes meeting.

McDonald, who will partner Neyali for Gai Waterhouse in the Blue Diamond, has been placed on standby for the Group One mount on Knoydart if the Darley sprinter takes his place in the Oakleigh Plate.

But first he is set to close in further on the Sydney jockeys' premiership leaders at Rosehill.

On potential, the John O'Shea-trained White Sage is a standout among his rides as the mare tries to make it six wins from as many starts in the NSW Thoroughbred Breeders' Classic.

McDonald will also ride the well-backed Twirl ($2.40) for Waterhouse in the Widden Stakes while he takes over on Junoob, the $2.30 favourite to win the Might And Power Handicap.

Yet there may be hidden depth to McDonald's book if Anthony Cummings is right about unraced two-year-old Mr Bogart.

Mr Bogart steps out for his first start in the Listed Canonbury Stakes and Cummings rates Gooree Stud-owned youngster a better prospect than his $21 quote might suggest.

"He'll play a part somewhere there through the autumn," Cummings said.

Mr Bogart ran a well-beaten second to the Waterhouse-trained Wandjina in a barrier barrier trial but Cummings wasn't fazed.

"Wandjina is well practiced, knows what it is doing and was out to win so the aim of the trial was a bit different to our horse," he said.