Cristoforo Colombo, ante-post market leader for tomorrow's Tattersalls Irish 2,000 Guineas, is not among the final 10 declarations for the valuable Curragh Group One.
The 2,000 Guineas fifth was a surprise defection from the Ballydoyle contingent, which now consists of Magician, Flying The Flag, George Vancouver and Gale Force Ten.
Since Tuesday, Magician, a facile winner of the Dee Stakes at Chester recently, had tumbled in the betting from a high of 14/1 for the season's first domestic Classic.
By Wednesday night, the gamble saw him trade as low as 4/1 and the decision of champion jockey Joseph O'Brien to ride him tomorrow confirms the impression that he is the elite operation's first string in the €300,000 contest.
Magician is now a clear 9/4 favourite, followed by Richard Hannon's Newmarket third Van Der Neer at 7/2.
Richard Hughes is booked to ride Van Der Neer, with Jamie Spencer aboard Hannon's second runner, Havana Gold.
Johnny Murtagh will partner Sheikh Mohammed's recent purchase Fort Knox, a general 11/2 shot to get the five-time champion jockey's training career off to a successful start.
Jim Bolger relies on Dante Stakes runner-up Trading Leather rather than his Derrinstown second Loch Garman, while First Cornerstone will make its seasonal reappearance in the race ahead of a tilt at next month's Irish Derby.
Eddie Ahern, meanwhile, will be backed by the Professional Jockeys' Association (PJA) in his appeal against the 10-year ban that the 35-year-old Templemore native incurred on being convicted of corruption by the British Horseracing Authority.
"Eddie is adamant that he is not guilty of the corrupt charges found against him and plans to appeal," said PJA spokeman Paul Struthers.
"We are supportive of this position given the concerns over the judgment and written reasons of the disciplinary panel."