Gai Waterhouse and Kerrin McEvoy have achieved more than most in racing but so far a Cox Plate win has eluded both of them.

The trainer and jockey get a chance to rectify that at Moonee Valley on Saturday when they combine with outsider Pornichet in the $3 million contest.

Waterhouse admits she covets a victory in the race regarded as the weight-for-age championship of Australasia.

"To think I've been able to get the Melbourne Cup, the Caulfield Cup, most of the other Cups in Australia," Waterhouse said.

"I'd give my eye teeth to be able to do it for the owners and the satisfaction. It would be lovely."

Waterhouse has put a tongue tie on Pornichet after the Doomben Cup winner weakened to finish last in the Caulfield Stakes at his most recent start.

His lead-up form in Sydney had been sound, including a placing behind Cox Plate rival Kermadec in the George Main Stakes.

"Caulfield can be a funny old thing. It has been a graveyard for a few good horses over the years," Waterhouse said.

Waterhouse noted that the horses who settled in the first four in the Caulfield Stakes finished at the back of the field.

But while Pornichet disappointed in that race the five-year-old has delighted his trainer since with his two gallops at Moonee Valley this week.

"He's a really happy horse and he'll run terrific," Waterhouse said.

McEvoy has won a Golden Slipper on Sepoy (2011), a Melbourne Cup on Brew (2000) and a Caulfield Cup on All The Good (2008).

He needs a Cox Plate victory to join an elite group of just seven jockeys to have won racing's grand slam.

"I'll be doing my best to try and get that last one of the top four," McEvoy said.

"There's only been a handful or so that have done it, won the four majors here. It would be a fairytale to be able to do it."

The closest McEvoy has come to winning the Cox Plate in six attempts was a third on Viscount in 2001.

He rode Pornichet in the Caulfield Stakes and felt the horse had excuses but conceded the Tulloch Lodge galloper needed to turn his form around.

"He just did a few things wrong. There's been a gear change which has worked really well I think," McEvoy said.

"He's obviously a Group One winner at weight-for-age in the Doomben Cup. He's got to bounce back but there's nothing to say in his work on Tuesday and Saturday that he's not in good form.

"He's at long odds but he's in good shape.

"If he can just conserve his energy and do it properly, he's got a nice finish on him.

"And we'll see how that stacks up in a great Cox Plate field."