Long Run has been ruled out for the remainder of the current campaign.
The Cheltenham Gold Cup and dual King George hero has been on the sidelines since finishing down the field in the Grand Steeple-Chase de Paris at Auteuil back in May.
Nicky Henderson's charge endured a rough passage back to Britain after that outing and he returned home to owner Robert Waley-Cohen to recover from his injuries.
The 10-year-old featured prominently in the ante-post lists for the Crabbie's Grand National but Waley-Cohen has announced he will not run this term.
He tweeted: "Long Run won't be ready to run this season. Greatly looking forward to seeing him racing again this autumn. First won in 2007 but only 10."
