Leading Investec Derby contender Telescope will not run in the Betfred Dante Stakes at York on Thursday.
Trained by Sir Michael Stoute, the Galileo colt went into winter quarters as a leading fancy for Classic honours on the back of a maiden win at Newmarket in September.
His only other start as a juvenile came when a promising second to Snow King on debut at Ascot earlier that month.
However, he was not among the eight runners declared at the 48-hour stage for the Knavesmire feature after picking up a minor infection which has developed in grazes on two of his legs, picked up when he was being loaded onto a horsebox.
Harry Herbert, racing manager to owners Highclere Thoroughbred Racing, said: "It's obviously very disappointing, particularly for all of his owners, that Telescope cannot run in the Dante on Thursday.
"Sir Michael couldn't give him anti-inflammatories as it was too close to the Dante and unfortunately we have discovered through a blood test that the grazes have become infected. We are hoping that he will still make it to the Investec Derby and Sir Michael is hoping to give him a racecourse gallop in preparation. "
Telescope's syndicate of owners include retiring Manchester United manager Sir Alex Ferguson.
Another of Highclere's syndicates will be represented in the Dante by Greatwood, who was a late withdrawal from Saturday's Lingfield Derby Trial because of the rain-softened ground.