The Melbourne Cup-winning rider teamed up with fellow Australian Jane Chapple-Hyam at Royal Ascot in June when Kaspersky ran a fine race to finish fifth in the Queen Anne Stakes.
Harley got back on board when the six-year-old returned to Berkshire for last month's Summer Mile, finishing second, but Payne was due to renew the partnership in this weekend's seven-furlong contest.
However, having picked up a virus after returning to Britain, she was forced to sit out Saturday's Shergar Cup and feels she is not well enough to ride Kaspersky on Saturday.
Chapple-Hyam said: "Michelle won't be riding. She was due to be here this morning but didn't come.
"Martin Harley will ride the horse again and we're very happy with him.
"We're coming back to seven furlongs. It was either that or go up to a mile and a quarter and after he ran so well in the Summer Mile, I felt seven furlongs was the better option for him.
"The weather doesn't matter to us as he goes on any ground, so all is good."
Chris Wall is ready to let his star filly Mix And Mingle take on the boys in the Group Two feature.
The daughter of Exceed And Excel won her first two starts of the campaign, including a Group Three victory over star French filly Qemah in the Chartwell Fillies' Stakes at Lingfield.
She disappointed in the Duke of Cambridge Stakes at Royal Ascot, but Wall is hopeful she can get her season back on track this weekend.
"She's been confirmed for the Hungerford and as long as we don't get a deluge of rain at the end of the week, the plan is to run," said the Newmarket handler.
"We had hoped to go for the Oak Tree Stakes at Glorious Goodwood, but unfortunately the ground went too soft, so we've just had to keep her ticking over.
"There was nothing for her between Ascot and Goodwood really and it was annoying we couldn't run her there.
"I think Ascot proved she doesn't stay a mile and just with the way the race was run, it didn't work out for her on the day.
"She'll be taking on colts on Saturday, which is not ideal, but she's in good form and we're looking forward to running her."
Kaspersky and Mix And Mingle are among 22 horses confirmed.
Last year's winner Richard Pankhurst is in the field once again, as is 2014 victor Breton Rock, who caused a 50-1 upset in the Lennox Stakes at Goodwood on his latest appearance.
The two Irish contenders are Aidan O'Brien's Spirit Of Valor and the Ger Lyons-trained Psychedelic Funk.