Ringaroses, from Henrietta Knight's West Lockinge stables, near Wantage, will miss next week's Coral Cup at the Cheltenham Festival after suffering an injury setback.
The seven-year-old was the 7-1 second favourite with the sponsors for the two-mile-five-furlong heat after finishing an eyecatching second to Backbord at Doncaster last time.
However, Knight has ruled out a run at the Festival and Ringaroses now faces an indefinite spell on the sidelines.
She said: "Ringaroses has pulled a muscle in his hind-quarters and will not be running next week."
The Tony Martin-trained Leg Spinner is the 6-1 favourite with Coral for the race.
Meanwhile, Knight's Calgary Bay is on course to tackle the opening Anglo Irish Bank Supreme Novices' Hurdle on Tuesday.
A winner at Cheltenham in December, the five-year-old has since been beaten at Sandown and Exeter where he found the testing ground against him.
"He is a chaser for next year," said Knight. "He is a very talented horse. He would have a chance, but maybe there will be a few nippier things."
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