Hong Kong-based Nash Rawiller has picked up the ride on one of the local Cox Plate contenders while his brother Brad is confident about his chances aboard an international visitor.

Nash Rawiller has been called on to ride the Chris Waller-trained Preferment in Saturday's $3 million race to replace the suspended Blake Shinn.

Hugh Bowman has chosen to ride Winx over stablemate Preferment.

Brad Rawiller partners French horse Gailo Chop and after riding the Cox Plate invitee in fast work on Saturday at Werribee and again in light exercise on Monday, he is convinced he is on a genuine chance.

"I couldn't be more impressed with how he feels, how he is going, how he's settled in. I think everything is ticking over perfectly," Rawiller said.

"When riding him on Saturday morning I wasn't sure what to expect, whether he would be a bit one-paced. But that was the best thing about riding him on Saturday in a strong gallop - his sharpness.

"He really impressed me."

Gailo Chop is a $26 chance in the Cox Plate but Rawiller is unfazed.

He noted Criterion, the equal favourite, finished just over a length in front of Gailo Chop in the Prince Of Wales's Stakes at Royal Ascot and said Criterion "had the drop on him" in that race when Gailo Chop finished eighth of nine.

Rawiller was impressed with Gailo Chop's last start Group Three win in a straight track 2000m race in France.

"I know what he can do and I'm going in there very confident that I've got the horse underneath me to do the job," Rawiller said.

Criterion and Kermadec are co-favourites at $5.50 with Highland Reel at $6 along with Winx while Preferment is at $11.

Both Nash and Brad Rawiller can count a Caulfield Cup and Golden Slipper among their Group One wins but neither has won a Cox Plate.

Brad has ridden in the race twice on Niconero (2007) and Avienus (2011), finishing 11th and 13th respectively, while Nash has ridden in 10 Cox Plates with his best results a second on Wonderful World in 2007 and a third last year on Silent Achiever.

Highland Reel will be striving to give Irish trainer Aidan O'Brien back-to-back Cox Plates after Adelaide won last year.

The final Cox Plate field will be announced on Tuesday morning with the barrier draw to follow.