Jamie Moore faces a lengthy spell out of action after breaking his back and sternum in a fall at Fontwell.
The jump jockey took a crashing tumble from Alka Step at the fifth-last fence in Tuesday’s attheraces.com Novices’ Handicap Chase.
Moore, 35, received treatment on track and was taken to Brighton Hospital for X-rays and further assessment.
His father, West Sussex trainer Gary Moore, said: “He’s fractured his back and also his sternum.
“He’ll be off for a while. We don’t know anything more at the moment.
“They are waiting to see if they are going to operate or not. We’re not quite sure yet.”
Twiston-Davies back next week
Sam Twiston-Davies is set for a few days on the sidelines following his fall at Fontwell.
The jump jockey was unshipped from Master Burbidge at the second fence in Tuesday’s Download The At The Races App Handicap Chase.
He suffered a kick to the mouth by another horse and needed stitches to a wound on his lip.
He was taken to St Richard’s Hospital in Chichester, and allowed home later.
Twiston-Davies father, trainer Nigel, said: “He’s fine, he’s back home.
“He’s had stitches on his lip. He got a kick in the mouth.
“I think he’ll be back within a week, hopefully.”