Blake Shinn has ridden Preferment in a Moonee Valley track gallop but trainer Chris Waller says that does not mean he will have the Cox Plate mount.

Waller said Hugh Bowman would decide between Preferment and Winx, both of whom he has ridden to their last-start wins, with Shinn to ride the other one.

"I could make it easier and make the decision for him (Hugh).

"I'm not going to get too fussed about it. I don't think the punters should either. Both riders are good and both suit whichever horse they ride."

Waller took his three Cox Plate contenders to Moonee Valley for solo workouts.

His Melbourne stable representative Justine Hales partnered Epsom Handicap winner Winx with Glen Boss on Kermadec, the jockey's Cox Plate ride.

The trainer was delighted with the way the three handled their gallops and said they would most likely head to the track for another hit-out on Tuesday.

"It was good. I can't really separate them, they were all on the right legs and finished off well under no pressure," Waller said.

"I didn't time the three but to my eye she (Winx) looked the sharpest.

"That means little in terms of how they are going to perform but she's a very sharp, athletic filly and she got around the track effortlessly on the right legs and it was quite impressive to watch."

Waller said Kermadec had come through his Caulfield Stakes fourth placing well and in retrospect he believed he might have been a little soft, with the race coming three weeks after his George Main Stakes win.

He said Preferment was a different type of horse to his stablemates in that he needed 2000m to excel and wasn't as sharp over shorter distances and in track gallops.