Dwayne Dunn has been entrusted with the ride aboard Contributer when he starts his Cox Plate campaign at Moonee Valley.

Dunn, runner-up in the Scobie Breasley Medal last season, will ride the six-year-old in the Group Two Dato Tan Chin Nam Stakes (1600m) on Saturday.

It will be Dunn's first ride on the Godolphin-owned Contributer who is the $11 equal favourite for the Cox Plate in October alongside Highland Reel and Pornichet.

The imported galloper hasn't raced since winning the Group One Ranvet Stakes at Rosehill in March before being a race eve scratching from the Queen Elizabeth Stakes at Randwick in April.

Contributer has emerged as one of Australia's leading weight-for-age performers since his arrival from the United Kingdom almost 12 months ago.

A winner at the Royal Ascot meeting in 2014, Contributer was shipped to Australia after he was bought by Sheikh Mohammed.

He won his first southern hemisphere start at Caulfield during last year's spring carnival before finishing eighth in the Emirates Stakes at Flemington.

He returned in the autumn winning on three occasions at weight-for-age in Sydney.

Dunn rode Calaverite to success for Godolphin in a Listed two-year-old race at Moonee Valley in March and said the opportunity to ride Contributer was too good a chance to bypass.

"While there's good races still going on in Sydney and they need someone here, I'm more than happy to fill in on a horse like him," Dunn said.

"You never know what that may lead to later on.

"You don't really expect to be riding them heading towards a Cox Plate, but still you have an opportunity and it's too good to let slip."

Contributer is expected to head to Moonee Valley on Tuesday for a familiarisation gallop at the track and Dunn said he would be happy to ride the son of High Chaparral in the work-out if required.