The Jim Bolger team have suffered a reverse with their Oaks hope Galatee who will now miss tomorrow's Epsom classic.
The unbeaten filly was supplemented into the race on Sunday for £20,000 and was a general 9 to 2 third favourite to emulate Bolger's 1991 Oaks heroine Jet Ski Lady.
"She has an elevated white cell count," the trainer explained yesterday. "We will look at the Ribblesdale Stakes at Royal Ascot instead."
That leaves the ante-post favourite Alexandrova as the sole Irish hope in the Oaks and Kieren Fallon will be on board the filly who will bid to secure Aidan O'Brien a third Oaks success.
The final steps are being put in place for O'Brien's four strong Derby challenge with confirmation yesterday that Kieren Fallon will be on board Horatio Nelson on Saturday.
And Michael Kinane (Septimus) and John Murtagh (Dylan Thomas) have also been snapped up.
Between them the three jockeys have won the last seven editions of the Derby and Kinane also has a 1993 success on Commander In Chief to his credit.
A rider has yet to be booked, however, for the 66 to 1 outsider Mountain.
The £75,000 supplementary entry Papal Bull, another Coolmore Stud hope, will have Dublin-born jockey Robert Winston on his back in the Derby. "I've had a sit on him and he's a lovely strong horse," Winston said.
"He has done nothing wrong and won his Derby Trial. The form has worked out okay too. It's something to look forward to."
The Ballydoyle team won the Coronation Cup last year with Yeats and Ace will be their representative in a small but select field tomorrow.
The Breeders' Cup winner Shirocco heads a six-strong entry for the race that will also include the 2004 Oaks winner Ouija Board who ran third in the Queen Elizabeth II Cup in Hong Kong on her last start.
On what will be a critical classic weekend, O'Brien and Fallon will also team up in Sunday's Prix du Jockey Club at Chantilly with Aussie Rules.
One other Ballydoyle entry could accompany that grey colt who landed the French Guineas at Longchamp on his last start.
Ruby Walsh was the top rider at the Punchestown festival and could have another bumper meeting at the track tonight.
Davenport Democrat looks thrown in to the handicap hurdle on his chase rating and although his four previous starts over flights were unsuccessful he looks worth another shout.
Snowy Morning was beaten a long way on his hurdling debut at Navan but the double point to point winner looks worth another shout in the three mile maiden while Woman Of Substance looks an obvious pick in the opener. The Galway Hurdle winner More Rainbows fell on his sole chase start to date at Tralee last August but Noel Meade's horse looks a stand out in the Beginner's Chase.
