Passage Of Time, ante-post favourite for the Vodafone Oaks, has been found to be suffering from a throat problem.
However, the Prince Khalid Abdullah-owned filly could still take in her planned prep race in the Tattersalls Musidora Stakes at York on Wednesday.
Lord Grimthorpe, racing manager to the owner, said in a statement issued to PA Sport: “After a routine endoscopic examination Passage Of Time was found to have a small abscess on her epiglottis.
“At this stage it has not affected her breathing and it is still the intention to run her in the Musidora Stakes at York on Wednesday.
“All being well she would then go on to the Oaks.”
Passage Of Time rounded off a successful juvenile campaign when landing the Group One Criterium de Saint-Cloud in November.