Joseph O'Brien is set to ride Cristoforo Colombo in the 2000 Guineas at Newmarket on Saturday.
Trainer Aidan O'Brien, who was speaking at Tipperary, also revealed it was the intention for Seamie Heffernan to ride the once-raced Mars in the Classic, with Colm O'Donoghue on George Vancouver.
A son of Henrythenavigator, Cristoforo Colombo's final start as a juvenile saw him finish fourth to Reckless Abandon in the Middle Park Stakes over six furlongs of the Rowley Mile course.
Mars has not been seen since winning a maiden on the Polytrack at Dundalk in July, while George Vancouver rounded off his two-year-old campaign with victory in the Breeders' Cup Juvenile Turf at Santa Anita in November under Ryan Moore.
Moore will ride Lines Of Battle for O'Brien in the Kentucky Derby on Saturday night, but the plan is for him to be back in Britain for the mount on Ballydoyle's Snow Queen in the Qipco 1000 Guineas on Sunday, where Joseph O'Brien will partner the supplemented Moth.
William Buick, meanwhile, believes he has picked up a good spare ride in Van Der Neer in the 2000 Guineas.
John Gosden's stable jockey is delighted to have been snapped up by trainer Richard Hannon, who is also responsible for the strongly-fancied Toronado, in the colts' Classic over the Rowley Mile.
Van Der Neer booked his place in the race with a smooth victory in the Listed International Stakes at Lingfield three and a half weeks ago on his seasonal debut.
He had smart form as a two-year-old, winning his first two starts before signing off with a creditable second place behind Kingsbarns in the Racing Post Trophy at Doncaster on October.
"I've not ridden him before, but I've seen him obviously and have ridden against him once," Buick told At The Races.
"He looks a nice horse and a good spare ride to get. I won't sit on him before Saturday. He seems to be very straightforward and he doesn't look to have any obvious quirks.
"He looked good at Lingfield and he ran very well in the Racing Post Trophy as well, so I hope it all suits him."