Robbie McNamara will miss the ride on Lord Windermere in the Crabbie's Grand National at Aintree after suffering a fall at Wexford on Friday.

The jockey was due to partner last year's Cheltenham Gold Cup winner in the world's most famous steeplechase, but trainer Jim Culloty will have to find a new rider for his stable star.

McNamara, who rode a double at last year's Cheltenham Festival as an amateur before turning professional earlier this season, was partnering 14-1 shot Bursledon when he came to grief four flights from the finish in the first division of the Cahore Point Handicap Hurdle.

He was taken to Wexford General Hospital, where he underwent a CT scan.

Dr Adrian McGoldrick, chief medical advisor for the Irish Turf Club, said: "He (McNamara) is definitely a non-runner tomorrow. He's having a scan on a potential spinal injury."