Leading jockey Robert Thornton is expected to be ruled out of the Cheltenham Festival due to an injury to his arm.
The 34-year-old, who is nicknamed 'Choc', fell at Southwell on Monday while riding Phylli Vera for trainer Alan King, and it is believed that the jockey will be out for the rest of the jump season.
Thornton wrote on Twitter: "Few tests yesterday, not great news looks like I'll be missing the rest of the season."
"When I spoke to him last night I realised things were pretty bad," BBC Sport quotes King as saying. "After the fall we all thought he was just badly bruised, but the scan has obviously said otherwise.
"I'm not entirely sure what the injury is, I believe he's done something to his arm. We'll get by, but I just feel so sorry for Choc. We're all absolutely gutted for him."
Thornton clinched the Top Jockey title at the Festival in 2007 by riding four winners.
