Barry Geraghty was taken to hospital this afternoon after a fall in the Aintree Topham Chase from Peregrine Run with a suspected fractured leg
The Meath man missed the ride on favourite Champ in the next race a novice hurdle with Mark Walsh deputising and going on to win on the JP McManus-owned horse.
"Hopefully Barry will be okay, he took a nasty fall," stated Walsh in a post-race interview.
Champ's trainer Nicky Henderson said: "We have a nasty feeling that Barry has broken his leg, which would be tragic."
He was due to ride the Tony Martin-trained Anibale Fly in the Grand National tomorrow.
Two horses - Forest Des Aigles and Crucial Role - were fatally injured on the second day of the meeting.
The Dan Skelton-trained Crucial Role fell in the Mildmay Novices' Chase, while Forest Des Aigles, trained by Lucinda Russell, was injured when in contention approaching the final fence in the Topham Chase.
Their deaths are the first at this year's Festival.
Geraghty was a guest at the launch of the Fairyhouse Easter Festival at the Stephen's Green club in Dublin and told the Meath Chronicle that "if in one piece, he'd be disappointed not to have a ride" in the Irish Grand National on Easter Monday.