Two three-year-olds will carry the hopes of Gai Waterhouse as the champion trainer chases the biggest trophy in Australian racing to have eluded her.

Waterhouse has won 126 Group One races and claimed the biggest win of her career when Fiorente claimed last year's Melbourne Cup.

Descarado gave Waterhouse her first Caulfield Cup in 2010.

But a Cox Plate is still missing from the trophy cabinet.

"I've got the two Cups, I need the saucer," Waterhouse said.

"And I'm telling you I'm trying really hard to get it.

"I've got two live chances."

Waterhouse has last season's Group One J J Atkins Stakes winner Almalad and Caulfield Guineas third placegetter Wandjina in the field of 14 for Saturday's $3 million Cox Plate.

"Three-year-olds have got a great record in the Cox Plate and they are two on-the-up horses," Waterhouse said.

Connections of Wandjina paid a $130,000 late entry and the Moonee Valley Racing Club committee accepted the colt into the final field on Tuesday.

Almalad won the Bill Stutt Stakes at Moonee Valley two starts ago and will be out to bounce back from a disappointing eighth in the Caulfield Guineas last start.

The trainer has had five placings in the Cox Plate, most recently thirds with Fiorente in 2013 and Pierro a year earlier.