The Ballydoyle handler has saddled High Chaparral (2001), Brian Boru (2002) and most recently St Nicholas Abbey (2009) to land the Town Moor Group One in the last decade and has Master Of Hounds and Seville in this year’s renewal.
Once news emerged this morning that stable jockey Johnny Murtagh had chosen the former – off the track since winning a Tipperary maiden in July – further money started to arrive.
Coral cut the youngster to 11-2 from 7-1, while Seville, the mount of Colm O’Donoghue, is out to 6-1 from 5s with Stan James.
O’Brien’s pair feature among a strong Irish challenge, with Casamento and Dunboyne Express the top two in the betting at this stage.
Mick Halford’s Casamento ran away with the Beresford Stakes at the Curragh on his latest start and will be ridden by Frankie Dettori, while the Kevin Prendergast-trained Dunboyne Express is unbeaten in two starts.
Toolain will be one of the outsiders having suffered defeat on his sole start in Pattern company at Ascot earlier this month, but his trainer Michael Jarvis feels he is better than he showed that day.
“We don’t think the Ascot run was his true running as he had been off the track since July, which is a considerable length of time,” said the trainer. “He’s a big horse and we just felt he was a bit rusty that day and while this is a big ask for him, we just felt it is the end of the year and we might as well have a crack at it.
“His earlier form is pretty good. He beat Mick Channon’s horse (Galtymore Lad) and he is a pretty good yardstick having run Wootton Bassett close twice.
“I wouldn’t think he’d want the ground too soft and ideally I’d like it to remain as it is.”
Dubawi Gold, Karam Albaari and Zaidan complete the 10-runner line-up. The only withdrawal from the five-day stage was O’Brien’s Treasure Beach.