Phantom Wind, one of the leading candidates for this afternoon's UltimateBet.com 1000 Guineas, has been ruled out of the Newmarket feature due to a high temperature.
John Gosden's charge had been prominent in the betting for the second Classic of the season following her sixth placing in the Dubai Duty Free Stakes at Newbury.
Gosden, who won the race with Lahan in 2000, said: "It's a shame, but that's racing. We have been battling against the clock, but we will now prepare for a tilt at either the French of Irish 1000 Guineas."
Phantom Wind's defection leaves a total of 16 to go to post for the mile contest. She was a best-priced 10-1 fifth favourite with the leading bookmakers.