Trainer Bryce Heys won't be offering up any excuses should Newmarket Handicap favourite Spieth be beaten at Flemington.

While the weather in Sydney hasn't hindered Spieth's preparation towards Saturday's Group One race, Heys admits it hasn't been ideal.

Then there's the 55.5kg for the non-Group One winner with the final straw being barrier one in the 13-horse field with Heys admitting he would have preferred a wider draw.

But Heys is happy with Spieth's condition ahead of Saturday's race as the four-year-old chases his first Group One win.

Spieth has been narrowly beaten at his past two starts, both at Group One level, the latest in the Lightning Stakes at Flemington on February 18.

Heys took the four-year-old back to Sydney after that run to the comforts of his home stable.

"The reason I did that was because of the three weeks between runs," Heys said.

"If it was two weeks I would have left him down.

"I just think he's a happier colt when at home and he knows where home is now."

Heys said the wet weather had not interfered with Spieth's preparation.

The trainer says Spieth has been weighted on potential and understands that he sits between Buffering (54.5kg) and Chautauqua (55.5kg) when given his 55kg original handicap.

Like Spieth, Buffering and Chautauqua were beaten in the Darley Classic, and failed to win the Newmarket the following year which, for Heys, makes Spieth's weight fractionally high.

Weights were raised half a kilogram on Wednesday when topweight Chautauqua was not among the acceptors.

"Buffering and Chautauqua are as good a generation of sprinters we have seen outside of Black Caviar and Hay List," he said.

With barrier one Heys said it will be up to Hugh Bowman to find the most economical run and then get into clear galloping room at the appropriate time.

Heys says he's got Spieth in perfect order and the narrow second in the Lightning to Terravista had brought him on fitness-wise.

"We've got a fit and healthy horse that performed well in the Lightning which traditionally is a good lead-up race for the Newmarket," Heys said.

"I've done my job and the rest is now up to Hugh."