Craig Williams' first racetrack appearance for the year will be at Warwick Farm on Saturday when he partners leading Magic Millions contender Assail in an exhibition gallop.

Recently returned from his annual stint in Japan, Williams will return to competitive riding at the Gold Coast on January 12 when he partners the Clarry Conners-trained Assail in the $2 million Classic for two-year-olds and Sizzling in the Magic Millions Guineas.

Williams replaces the suspended Peter Robl on Assail and has picked up the ride on Sizzling with Chris Munce to begin treatment for tonsil cancer next week.

Conners said Assail, co-favourite with Clevadude, had done well since her emphatic Wyong Magic Millions win and Robl was also pleased with her track work.

"Peter rode her this morning and he was happy," Conners said.

"Craig will come up on Saturday to work her between races. I really want him to get a feeling for her.

"She goes to the Gold Coast on the Tuesday night and then I will be sleeping with her until Saturday."

Conners is a shareholder in Assail who has won both of her starts, the first over 1000m and the 1100m Wyong race.

The trainer is confident she can be just as effective over the 1200m of the Magic Millions for which she and Clevadude dominate at $3.50 with Missy Longstocking a $12 chance.