Haskoy, a leading contender for the Gold Cup at Royal Ascot, has been retired after straining a tendon.
Trained by Ralph Beckett, Haskoy did not make her racecourse bow until last July, when she ran out a seven-length winner on the all-weather at Wolverhampton.
The daughter of Golden Horn made rapid strides, winning a Listed race at York before coming home second in the St Leger, although the filly was demoted to fourth after causing interference in the closing stages.
Haskoy was as short as 5-1 for the Gold Cup after a game Group Three victory on her Newbury return last month, but the setback means she will now head to the paddocks rather than the Royal meeting.
Beckett tweeted: “Haskoy has strained a tendon, consequently she is being retired to the paddocks.”
