Riverside Theatre has been ruled out of this year’s Ryanair Chase after suffering a hairline fracture to his pelvis.
The superstar was last seen cruising to victory in the Betfair Ascot Chase last month and had been a clear second favourite for his Cheltenham Festival target.
Riverside Theatre has been in fantastic form this season and his Grade One victory at Ascot came after he beat Kauto Star when chasing home Long Run in the King George VI Chase at Kempton.
Henderson is confident that the talented chaser can recover from his injury and he explained: "Riverside was lame after exercise on Friday and, as a result, we found he had suffered a hairline fracture to his pelvis. Although we hoped the problem was muscular, a scan revealed that to be not the case.
"He's lucky this has been revealed, rather than anything more serious, as the consequences would have been bad. I have spoken to the vets and we are confident he'll be perfectly fine for next season.
"It's still an enormous shame as he was having a most promising season. He's still young, though, and will hopefully have a huge career."