Champion Winx and her jockey are fit and ready for the Queen Elizabeth Stakes but her main rival Happy Clapper will have a new rider in the $4 million race.

Kerrin McEvoy will replace Blake Shinn who has won three Group One races on Happy Clapper but has a commitment to the Darren Weir-trained Humidor who he rode to run second to Winx in the Cox Plate.

Happy Clapper won Saturday's Doncaser Mile a few hours after Winx made a cameo appearance at Randwick for a race day gallop with Hugh Bowman aboard.

Bowman's autumn carnival has been interrupted twice by illness, firstly because of concussion after a race fall from Performer in the Todman Stakes and again when he was stood down at Warwick Farm last Wednesday week with a viral condition.

He was originally told to spend two weeks recovering but gained a medical clearance on Friday in time to ride the mare in her work-out.

He said he felt much better and more importantly Winx felt as good as she has throughout the autumn during which she has won her two starts in the Chipping Norton Stakes and George Ryder Stakes.

On Saturday she will be attempting her 25th straight win and her 18th at Group One level with her trainer Chris Waller saying Bowman was an integral part of the process.

"Anybody could ride Winx but expecting anyone to cope with the pressure that goes with riding Winx is a big ask," Waller said.

"He knows her and he knows me better than anyone else apart from my family and it makes my job so much easier.

"There is a process in place and it's a matter of making sure it all fits together."

Just how important her jockey is was demonstrated when connections opted to delay her return and miss the Group Two Apollo Stakes in February when Bowman was suspended.

She went first-up into the Chipping Norton Stakes over 1600 metres and back to 1500 for the George Ryder.

Winx steps up to 2000 for the Queen Elizabeth for which she is the $1.15 favourite ahead of Happy Clapper at $9.

Humidor and his stablemate Gailo Chop are at next at $11.