Santiago the choice of Heffernan as Ballydoyle launch six-strong Irish Derby bid

Aidan O'Brien will launch a six-strong attack on Saturday's Dubai Duty Free Irish Derby, with Queen's Vase hero Santiago, the choice of Seamie Heffernan, and King Edward VII Stakes second Arthur's Kingdom set to turn out quickly after their highlighting their Classic credentials last week at Royal Ascot.

In the most unusual season where the Curragh prize precedes the Epsom highlight, the Ballydoyle squad make up 40 per cent of the 15 runners declared on Thursday, with Santiago the 3-1 favourite to provide the master trainer with an incredible 14th win in the race.

Arthur's Kingdom, who will sport first-time cheekpieces and is next in the market at 5-1, is the mount of Wayne Lordan.

Speaking on a webinar building up to the much-anticipated Saturday night showdown, O'Brien said of the market leaders: "When Santiago ran at Ascot he was very fit coming into it. We think the Curragh will suit him and that's why he's going back. Arthur's Kingdom is the same."

Santiago: opened his account at Listowel last year under Donnacha O'BrienCredit: Patrick McCann

He added of the of the unorthodox campaign: "It's been the same for everybody, but it's going to be unusual and things could happen that none of us expect would happen.

"Horses won't improve and some will improve. We would usually like to have two runs into them well spaced out before the Derby. Most horses are only after having the one run now.

"I think it's probably going to be the most exciting of all because there is so much mystery in it."

There was also news from the Tipperary base on Thursday regarding the Ballydoyle contenders for the Investec Derby on Saturday week, with Royal Ascot scorer Russian Emperor set to be Irish 2,000 Guineas second Vatican City and Mogul, who disappointed in the King Edward VII Stakes behind Pyledriver.

Pyledriver: got the better of Arthur's Kingdom in the King Edward VII Stakes last weekCredit: Alan Crowhurst

Amhran Na Bhfiann and Mythical are also in contention for the Investec-sponsored prize, while Armory is described as a possible runner at this stage, with the French Derby also an option for him along with Fort Myers.

O'Brien is optimistic that the Group 2-winning juvenile from last season can come forward a fair deal from his seasonal bow.

"Mogul needed two runs, really, before the Derby but we weren’t able to get two runs into him," he explained.

"We ran him in the toughest race over a mile and a half and we’re kind of asking one race to do two races’ job. Because of that, we had to give him some extra time and we're hoping he might come back for Epsom."

He added: "We had worked him as hard as we could but some horses need racing to get them there. He was very vulnerable going to Ascot but we thought that going to Epsom, he probably had to have a tough mile and a half somewhere.

"Russian Emperor looks to have come out of Ascot well. He hasn’t done a lot but he seems to be in good form."

Aidan O'Brien on Mogul: 'He was very vulnerable going to Ascot but we thought that going to Epsom, he probably had to have a tough mile and a half somewhere'Credit: Alan Crowhurst

It could be a hugely significant weekend for the O'Brien camp at Irish Flat racing headquarters this weekend, with star mare Magical, who had originally been retired at the end of last season, in line to return in Sunday's Alwasmiyah Pretty Polly Stakes.

Last year's shock Irish Derby scorer Sovereign, absent since that famous success under Padraig Beggy, will also make his comeback in the Group 3 Comer Group International Vintage Crop Stakes on Saturday.

Wolferton Stakes runner-up Sir Dragonet will make a quick turnaround to line up in Saturday's Dubai Duty Free-sponsored Alleged Stakes (Group 3), with a tilt at the King George VI And Queen Elizabeth Stakes back at Ascot being considered after this weekend.

Magical (right) gave the mighty Enable a scare in last year's Coral EclipseCredit: Edward Whitaker

"Magical is going to start back and we're also thinking of running Fleeting," O'Brien said of his Pretty Polly team.

"We weren't expecting to have her this year and it's great that the lads reconsidered and let us have her for another year. She had planned on going to No Nay Never but that just got pushed back a year. She did very well over the winter."

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