Vancouver's first northern hemisphere start has been delayed with last year's Golden Slipper winner to miss the Greenlands Stakes.

The colt had been scheduled to run in the Group Two sprint on Saturday (Sunday AEST) at the Curragh but trainer Aidan O'Brien said his blood count was unsatisfactory.

O'Brien still hopes to get Vancouver to the Diamond Jubilee Stakes at Royal Ascot despite the interruption to his campaign.

"It's unfortunate as we were keen to run him with Royal Ascot in mind," O'Brien said.

Vancouver will stand his first season at stud at Coolmore Australia in the spring.

The Tom Hogan-trained veteran Gordon Lord Byron, winner of the 2014 George Ryder Stakes in Sydney, will take his place.

"He'll improve for the run, I'd say, but he's in good form and we're happy to let him go," Hogan said.

O'Brien will be represented by Dick Whittington.