Snow Fairy has been ruled out of the Prix de l'Arc de Triomphe and the remainder of the year with a leg injury.
The Ed Dunlop-trained mare originally suffered the problem last season, with many claiming that her career was in jeopardy.
However, the five-year-old proved the doubters wrong to return to win the Irish Champion Stakes.
Now though, she faces another spell on the sidelines with the same tendon problem.
"She worked yesterday and we were very pleased with her, but last night we found just a little bit of heat in the leg," said Newmarket trainer Dunlop.
"Taking everything into consideration with the previous injury she's had, it was too much of a risk to carry on, so we've pulled stumps."
Snow Fairy recently broke the Leopardstown track record.