The jockey suffered hand and eye injuries in a tumble from Arctic Buck in the Kilgobbin Beginners Chase. He was released from hospital in Dublin on Sunday and was to receive further treatment from Dr Michael Foy in Lambourn last night.
His agent, Dave Roberts, said: "Norman is in good form. I am very confident he will be OK for Aintree. He is stood down for seven days due to concussion and we should have more idea by the weekend how long he will be off."
Williamson appears to have had a lucky escape. The Irish Turf Club medical officer Dr Walter Halley, who attended the stricken jockey straight after the fall, said: "He was initially unconscious but had come round when I got down to the fence."
Initially, it was feared that Williamson had fractured a wrist, an injury that could have kept him out for two months.Reuse content