Queen's Logic will miss today's Sagitta 1000 Guineas after the foot problem which caused her to be lame yesterday morning failed to improve overnight.
A spokeswoman for trainer Mick Channon's yard said: "She will not be running."
The news is a major blow to Channon who had high hopes that the Grand Lodge filly would provide him with his first Classic success.
Queen's Logic's injury was discovered at 5.30am yesterday and vets and farriers had been working round the clock in an attempt to get the filly sound.