Harry Skelton will miss the Scottish Grand National meeting after he injured his shoulder in a fall at Cheltenham.
The top jockey came off Heltenham in a race on Wednesday and gave up the rest of his rides on the afternoon.
Skelton, 33, will visit a specialist on Friday to see whether he can make it back for the end of the jumps season. His wife Bridget Andrews will take his place on most of his scheduled rides tomorrow at the Scottish track.
Coral Scottish Champion Hurdle entrant L'Eau Du Sud, a horse part-owned by Sir Alex Ferguson, was one of the horses he was due to team up with Saturday.
After training Walk In Clover to win on Thursday's card at Prestbury Park, Skelton's brother Dan said: "Harry has hurt his shoulder. It's a time of year where you give yourself plenty of time so I think whatever the prognosis is, I think he can add a little bit of self control into that as well and if he needs any longer..
"He's going to see a specialist tomorrow just to make sure there's not too much unknown damage. He said he feels quite good, so that's a positive but if he needs x (number of) weeks, he might take x plus two because of the time of year it is just to be triple sure."
Last weekend, the Skelton brothers raced to a double on Grand National day at Aintree.
West Balboa pulled clear in the Village Hotels Handicap Hurdle, before Midnight River stayed on best to win the William Hill Handicap Chase.
The Alcester stable, currently operating with a 20 per cent strike rate, has ten entries for Ayr's two-day fixture.
Walk In Clover kept the ball rolling with a three-length score in Cheltenham's Grade Two British EBF Mares' Novices' Limited Handicap Chase Final.
It was a first triumph at the track for jockey Tristan Durrell on the daughter of Walk In The Park, previously winless in six starts over fences and a stone out of the weights.
"The race today was a significantly different scenario as they were going to go a fair gallop and it was going to be a truer run race, so I’m very happy," Dan Skelton said.
“It’s important for these mares to get some black type and she’s got a phenomenally good family behind her."
