Poet's Word has suffered an injury setback and will not be seen in action again this year.
The Michael Stoute-trained five-year-old has been one of the stories of the season, beating Cracksman in the Prince of Wales's Stakes, before getting the better of stablemate Crystal Ocean in an epic finish to the King George VI And Queen Elizabeth Stakes.
His latest start came in the Juddmonte International at York, where he was second to Roaring Lion.
Stoute said in a statement issued to Press Association Sport: "Poet's Word has sustained an injury and will not be able to race again this year.
"His owner, Saeed Suhail, will soon be coming to England and will make a decision on his future."
A regular in the top races, Poet's Word was second in both the English and Irish Champion Stakes last season, and began this campaign when runner-up to Hawkbill in the Sheema Classic at Meydan.