Hartnell's defection to tackle the Cox Plate has boosted trainer Ciaron Maher's Caulfield Cup hopes, leaving Jameka as the horse to beat in the $3 million handicap.

The Maher-trained Jameka finished 3-1/4 lengths second to Godolphin's Hartnell in the Turnbull Stakes and was the same margin ahead of the next horse home.

Maher can't fault the Caulfield Cup favourite leading into Saturday's 2400m race.

"I was pleased (Hartnell isn't in the Caulfield Cup) because I think it was going to be a similar weight spread to when they met in the Turnbull, so he probably would have done the same thing to them," Maher said.

Jameka continued her Caulfield Cup preparations with a solo 1200m course proper gallop at Caulfield on Tuesday.

"She's pretty right where she's at," Maher said.

"She's had two runs at 2000 metres and now she goes out to a mile and a half on her home track, dropping to handicap conditions. There's a bit to like about it.

"It's hard to line them up but I'm certainly happy with her and hopefully her best is good enough.

"We've trained her to peak for her next couple of runs and I think she's improved every start this campaign. And Saturday should be no different."

Nick Hall, winner of the 2013 Caulfield Cup on Fawkner, has the ride.

Jameka was a dominant winner of the Naturalism Stakes two starts ago and can become the first Naturalism winner to win the Caulfield Cup.

Maher said Set Square, who also galloped solo on Tuesday, was looking for 2400m.

"She's held her condition really well this campaign," he said.

Maher has often said there's not a lot between Jameka and Set Square.

"Jameka is probably just a bit more adaptable in the way she races and she probably looks that bit sharper now," Maher said.

"Set Square might be just a little bit more dour."

Michael Dee gets his first Caulfield Cup ride on Set Square with fellow apprentice Ben Allen riding Saturday's Herbert Power Stakes third placegetter Pemberley.

"Pemberley drops to 50-1/2 kilos and when horses get to that sort of weight they can do things they haven't done before," Maher said.