Nicky Henderson has ruled Daphne Du Clos out of the Weatherbys Champion Bumper at next week's Cheltenham Festival.
The four-year-old filly had been second favourite for the race behind Willie Mullins' Carter McKay after her easy win in a Listed heat at Newbury last month.
She would have been in receipt of all the allowances at Prestbury Park but has picked up a minor problem which has brought her season to a premature end.
Henderson tweeted: "Daphne Du Clos has picked up a tiny problem which rules her out of the Cheltenham Bumper. It's a terrible shame but she'll be back next year."
Joseph O'Brien is keen to have another crack at Carter McKay with West Coast Time.
A son of Refinement, who finished second in the race for Jonjo O'Neill back in 2004, West Coast Time was beaten two and a quarter lengths by Carter McKay at Naas last month, but O'Brien feels a stronger run race will suit his charge better.
"They went very slow and sprinted (at the finish). The winner was very good. I don't know if we'd beat him or not but I'd like to think that we'd be able to get with him at the furlong marker some day and see what would happen after that," he told the Irish Independent.
"The horse's dam, Refinement, was second in it and she was a good mare. It would unbelievable to have a horse with a chance in the race.
"He'd have to have an each-way chance. He was very impressive in Cork, the race will be run to suit him I'd say and he'd like soft ground. He won well on soft ground. We'll know about that closer to the time."