A Kermadec win in the Cox Plate will be Glen Boss' fourth in the weight-for-age championship.

After victories on Makybe Diva (2005), So You Think (2009) and Ocean Park (2012), Boss will join Jack Purtell and Brent Thomson on four wins, one behind Darby Munro if successful on Saturday.

Kermadec is an easing $7 fourth favourite with Highland Reel remaining favourite at $5 ahead of Criterion at $6 and Winx at $6.50.

Boss said Kermadec would be suited by more favourable track conditions on Saturday after rain and irrigation put it at the end of the good range on Friday.

The jockey said Kermadec felt the ground at his last start when finishing fourth behind Criterion in the Caulfield Stakes.

"He's going to get a better surface on Saturday," Boss said.

"I've always said his best form is when there's cut in the ground and the first time he got on a rock-hard track was at Caulfield.

"He's finished beside the Caulfield Cup winner Mongolian Khan and was beaten by a superstar in Criterion.

"I think on the right surface my horse can turn the tables."

Boss said the Cox Plate had all the hallmarks of being a great race with Irish star Highland Reel the horse who interests him the most.

"They all say he is better than Adelaide," Boss said.

"They (Coolmore) know the formula now to win a Cox Plate, so they've probably brought the right horse again."