The Grand Prix Stakes shapes as a litmus test for a future Derby campaign for emerging stayer Mr Gee.

Trainer John O'Shea is confident Mr Gee will cope with 2400 metre assignments in the long-term but he is keen to see how the gelding adapts to the newly renovated Eagle Farm track with a view to next year's winter carnival.

"He is a very talented young stayer," O'Shea said.

"Saturday will determine his immediate future. I had envisaged this was a preparatory run for the Queensland Derby and an assessment of whether he was suited at Eagle Farm. We're going to learn a lot on Saturday.

"The tyranny of distance is no consequence for him. He will eat up a mile-and-a-half so we just want to wait and see what happens on Saturday."

Mr Gee is chasing a hat-trick of wins after victories at Kembla Grange and Hawkesbury where he defeated an older group of stayers in benchmark 64 company over 2000 metres on December 13.

His pathway to the Grand Prix is strikingly similar to the one Gerald Ryan pursued with last year's winner Chains Of Honour, who claimed a class two race at Hawkesbury before his dominant victory at Eagle Farm.

If Mr Gee does not handle the Eagle Farm track, O'Shea will scrap a Queensland Derby mission and concentrate instead on the autumn carnival in Sydney.

O'Shea said the Grand Prix will be the final start of Mr Gee's first racing campaign.

"He will be in the paddock on Monday," he said.

Mr Gee is raced by highly-successful owner Neil Werrett, who was thrust into the international limelight through the deeds of his invincible champion Black Caviar.

The Maher-Eustace stable is confident Toscanini can cope with a stamina test in the Grand Prix.

Toscanini is yet to race beyond 1615 metres but stable spokesman Jack Bruce believes the colt is equal to the challenge.

"His run three weeks ago at Rosehill was full of merit and he indicated that day he was looking for a trip," Bruce said.

"Even though he's going from 1500 metres to 2200 metres he's a very clean-winded horse and the team believes it's well within his capabilities."