French Derby winner The Grey Gatsby will not run in Saturday's Qipco Champion Stakes at Ascot because of the likely soft going.
Ryan said: "I'm not going to run him on heavy ground. He's done everything we've asked of him this year.
Dual winner Wise Dan has been ruled out of the Breeders' Cup Mile.
The seven-year-old gelding, trained by Charles LoPresti, returned with victory at Keeneland earlier this month but has been sidelined by an ankle injury.
"We won't decide if he will return to training until we see if he heals perfectly because he has nothing left to prove," said owner-breeder Morton Fink.
|Qipco British Champions Day, Ascot, Saturday 18 October (all times BST)|
|13:45 Long Distance Cup (Group Two) two miles|
|14:20 Sprint Stakes (Group Two) six furlongs|
|14:55 Fillies & Mare Stakes (Group One) one-and-a-half miles|
|15:30 Queen Elizabeth II Stakes (Group One) one mile|
|16:05 Champion Stakes (Group One) one-and-a-quarter miles|