Galileo Rock will not run in the English St Leger on Saturday unless the going improves at Doncaster.

Trainer David Wachman says he will switch his dual Derby-placed colt to the Irish St Leger at the Curragh on Sunday should he deem the ground at the South Yorkshire course to be unsuitable.

"Galileo Rock will be declared for the Irish St Leger and a decision on which race to go for will be delayed until tomorrow evening," said the County Tipperary handler.

"I want very much to run Galileo Rock in the English St Leger because of its prestige, prize money and the fact it is confined to three-year-olds."

Galileo Rock, third in the English Derby and second in the Irish equivalent, was among a field of 11 at the final declaration stage for the Doncaster Classic.

Aidan O'Brien bids to win the world's oldest Classic for a fourth time by saddling Queen's Vase winner Leading Light and the lightly-raced Foundry, who booked his place when runner-up on his seasonal debut in the Great Voltigeur Stakes at York.

O'Brien's son Joseph rides Leading Light with Ryan Moore booked for Foundry while the Ballydoyle trainer removed his other entry, Eye Of The Storm.