Monalee has been ruled out of the remainder of the national hunt season by trainer Henry de Bromhead.
The 10-year old had been set for another tilt at the Cheltenham Gold Cup, but injury has put paid to that plan.
Monalee made his seasonal reappearance at Tramore in November, placing third behind Presenting Percy and Kemboy in the Boomerang.ie Steeplechase.
Travel restrictions ruled him out of the King George VI Chase at Kempton Park on St. Stephen's Day, with a fitness setback meaning he also missed the fallback option of an outing at Tramore on New Year's Day.
"We're not quite sure how long he'll be out for yet, but he's unlikely to be back this season," De Bromhead told Sky Sports Racing, "We're just waiting for more information, then we'll see.
"It's very disappointing for that to happen, but hopefully we'll get him back on track again."
Monalee came home fourth, four lengths behind winner Al Boum Photo in last year's thrilling renewal of the Cheltenham Gold Cup.
Al Boum Photo again heads the betting for the blue riband event, which is likely to play out behind closed doors at Prestbury Park.
A Plus Tard and Minella Indo are De Bromhead's main challengers to Willie Mullins' all-conquering 9-year old.
De Bromhead is particularly confident of A Plus Tard's chances of toppling Al Boum Photo following an impressive victory in the Savills Chase at Leopardstown.
"That was a great day. He was really good and we were really delighted he did it so well in the end," the trainer said.
"We've entered him for the Gold Cup and the Ryanair and I'd imagine we'd be leaning towards the Gold Cup at this stage, but obviously we'll keep our options open and confirm nearer the time."