A winner at the meeting last year for the Supreme Racing Club and Willie Mullins, the eight-year-old was being prepared for a crack at the showpiece event.
However, the injury-plagued grey has met with another hiccup.
Racing manager Steve Massey said: “We’re absolutely gutted. I only saw him last week and he looked a million dollars.
“It’s nothing serious, not career-threatening or anything, he just needs box rest. It’s a different injury to the one he had before.
“He’s our flagship horse and for our members to have a runner in the Ascot Gold Cup was the stuff of dreams.
“We were all looking forward to it so much and I’d only booked my hotel yesterday.
“He’ll be back, it just sums racing up. We had a winner at Punchestown last week and now this happens. He might be eight but he’s got low mileage.”
Meanwhile, Leopardstown are seeking a new sponsor for the race best known as the Hennessy Gold Cup after the current backer ended its 25-year association with the race.
The three-mile event was first run in 1987 as the Vincent O’Brien Irish Gold Cup, with Hennessy beginning its sponsorship of the Grade One contest in 1991.
However, Edward Dillon & Co, which distributes Hennessy in Ireland, has opted not to continue their support of the race.
Chief executive Andy O’Hara said: “In this our 250th anniversary year and following the 25th running of the Hennessy Gold Cup, we have reluctantly decided not to extend the sponsorship beyond 2015.
“We have had a wonderful long-standing relationship with Leopardstown over the years and we thank them for their dedication and commitment to this multifaceted sponsorship.”
The likes of Carvills Hill, Beef or Salmon, Dorans Pride, Florida Pearl, Neptune Collonges and Sir Des Champs all feature on the roll of honour and Leopardstown’s chief executive Pat Keogh believes the race provides an excellent sponsorship opportunity.
Keogh said: ”We are extremely grateful to Hennessy for their huge contribution to Leopardstown over the past 25 years.
“Gold Cup Day at Leopardstown is one of the premier sporting occasions each year and is the only race day in Ireland with four Grade One races.
“This is a wonderful opportunity for a new partner to become part of a very special sporting event.”
Meanwhile, Horse Racing Ireland (HRI) have announced Limerick will host a National Hunt meeting next Tuesday to replace the meeting at Ballinrobe, which fell foul of the weather on last Tuesday after total of 31 millimetres of rain fell.
- Yesterday’s meeting at Brighton was abandoned after two races.
An inspection took place before racing due to very high winds, but the jockeys were happy for the fixture to start.
However, before the third race the matting which covers several roads which cross the course was lifting due to the strong gusts of wind.
“Safety has to come first, if anything happened and a horse came down we can’t take that risk,” clerk of the course Ed Arkell said.