Donnacha O'Brien will partner second-favourite Sir Dragonet in the William Hill St Leger at Doncaster on Saturday, with Ryan Moore on duty for Ballydoyle at Leopardstown for the first day of the Longines Irish Champions Weekend.
A general 3-1 shot behind even-money favourite Logician for the Doncaster Classic, Sir Dragonet will attempt to give Aidan O'Brien his seventh St Leger victory, and a third consecutive win in the race he won last season with Kew Gardens and with Capri in 2017 – both ridden by Moore.
Speaking on Wednesday, O'Brien said: "The plan is that Ryan will be riding at Leopardstown and Donnacha will be going to Doncaster.
"Il Paradiso and Norway are likely to join Sir Dragonet in the St Leger and we'll decide in the morning if any of our other three entries for the race will run."
South Pacific, Western Australia and Barbados are Ballydoyle's remaining St Leger entries.
Donnacha O’Brien will ride in the St Leger for the third time and seeks a fourth British Classic success having won the 2018 Oaks on Forever Together, and the 2,000 Guineas aboard Saxon Warrior in 2018 and Magna Grecia earlier this year.
An eight-length winner of the Chester Vase under O'Brien in May, Sir Dragonet finished fifth in the Derby before returning from a 76-day break to finish fourth in the Group 3 Royal Whip Stakes at the Curragh last month.
Moore looks set to ride Magical in the Qipco Irish Champion Stakes, a race he won on The Grey Gatsby in 2014, and dual Classic winner Hermosa in the Coolmore "Fastnet Rock" Matron Stakes.
O'Brien added: "We won't be finalising plans for the Leopardstown Group 1s until declaration time on Thursday. We'll probably have a few runners in both races and it's quite possible that Anthony Van Dyck will run in the Champion Stakes rather than in the Prix Niel at Longchamp on Sunday."
O'Brien has sent out seven winners of the Irish Champion Stakes but has not won the Group 1 since So You Think triumphed in 2011.