The $3-million, 2000-metre feature at Moonee Valley is Australia's premier weight-for-age race.

Yendall said he was excited about the opportunity to ride for Gai Waterhouse in one of the three biggest races in Melbourne.

"It's my first Cox Plate," he said.

"My big goal is to win a Group 1 race.

"To win a Cox Plate would be even better."

Wandjina's owners paid the $130,000 late entry fee for the three-year-old Snitzel colt, which just scraped into the plate field.

He is one of three three-year-olds in this year's event, along with Waterhouse-trained Almalad and John O'Shea's Sweynesse.

Under the conditions of the race, the three-year-olds will carry 49.5 kilograms, 9.5 kilograms less than the top seven runners. Wandjina has drawn barrier five and is a $35 chance at the TAB.

Yendall said the barrier was ideal and that he would have no problem with the weight.

"I think he's got a really good chance," he said. 

Despite not having the best form, Wandjina showed significant speed when coming from last to finish third in the Caulfield Guineas.

Waterhouse told The Age he had always had speed. "He just needed to know how to manage it," she said. "He was the fastest yearling I had and then the fastest two-year-old, but it has taken until now to put it all together.

"The speed is something they have to have though, and he has it. He's probably a miler, but milers win Cox Plates."

Yendall, one of the state's most prolific jockeys, is enjoying a busy spring.

He rode a double at Geelong on Wednesday and claimed a first and a second at Ballarat on Thursday.

"I've had a couple of good days," Yendall said.

"I'm flat out at the moment, which is good."

The Cox Plate will be run at 5.40pm.