Chris Waller will wait until acceptance time before naming a replacement jockey for Kermadec in the George Main Stakes.

Waller has been left without a rider for the Doncaster Mile winner on Saturday after Melbourne jockey Glen Boss lost an appeal against a careless riding suspension.

Boss won the Doncaster on Kermadec and he has been on the horse's back in two spring runs that have brought the four-year-old close to his best for the Group One race at Randwick.

"We won't be making a decision until the morning," Waller's racing manager Liam Prior said.

Bookmakers offering early odds on the George Main have Kermadec favourite at $2.90 ahead of stablemate Royal Descent at $4.80.

Kermadec confirmed he is well on the way to winning at Group One level for the second time with his last-start Chelmsford Stakes placing after having the hardest run in the race.

After he was sent forward from a deep barrier, Kermadec was trapped on a limb before finishing second to Complacent.

But as he showed in his Doncaster Mile win when allowed to settle worse than midfield, Kermadec is a much better horse when ridden from behind.

The entire shares the second line of Epsom Handicap betting behind stablemate Winx although Waller has indicated Kermadec will miss next month's $1 million race in which he has 56kg.

Instead, Kermadec is likely to be switched to Melbourne to contest the Caulfield Stakes as his lead-up run to the Cox Plate.

Waller also has veteran Moriarty and first-up disappointment Flamingo Star nominated for the George Main.

It's an entry matched in size by Godolphin trainer John O'Shea who has nominated It's Somewhat, Magic Hurricane, Sweynesse and the ATC Australian Derby runner-up Hauraki.

Jockey Blake Shinn expects Pornichet to announce himself as a genuine Cox Plate chance when he comes up against Kermadec.

"Obviously it's a quality field but he's a Group One horse and the race is going to see where he sits in terms of the Cox Plate," Shinn told Thoroughbred Central.

Pornichet barely earned a pass mark in the Chelmsford but Shinn said there were extenuating circumstances.

"Last start it wasn't ideal because the track played leaderish and he drew barrier 11 and he didn't have the speed to lead," Shinn said.