The Alvechurch handler aims to use the two-and-a-quarter-mile Group Two prize on Town Moor as a prep race for the Betfred Cesarewitch at Newmarket in October.
After bolting up on his penultimate start at Goodwood, the son of Teofilo, who won the Imperial Cup over hurdles at Sandown in March, followed it up with a tenacious success in the Northumberland Vase at Newcastle last month.
Williams said: "London Prize is having some time off, but will go for the Doncaster Cup, then on to the Cesarewitch which is his big autumn target.
"Fran Berry was surprised he won at Newcastle last time as they went slow and he is a real stayer. I'm not quite sure how good he will end up being on the Flat."