A late setback has ruled Dysart Enos out of the Ryanair Mares’ Novices’ Hurdle on day three of the Cheltenham Festival.

Fergal O’Brien’s star mare has won each of her six starts to date, with three bumper triumphs last season followed by a hat-trick of victories over hurdles this term.

The six-year-old was Britain’s biggest hope in Thursday’s penultimate event against two unbeaten Irish raiders in Gordon Elliott’s Brighterdaysahead and the Willie Mullins-trained Jade De Grugy, but she was declared a non-runner on the morning of the race.

O’Brien said: “It’s a huge blow, she’s got an overreach unfortunately.

“It’s not serious, it’s just horrendous timing. If it had happened earlier we might have been able to do something about it, but that’s where we are.

“We’ll get her right before we make any plans.”