Tony McCoy's intended Coral Scottish Grand National mount Benvolio has been declared a non-runner in Saturday's feature event.
The 19-times champion was due to partner the eight-year-old for Paul Nicholls in what would have been his final ride in the Ayr contest before he retires next week.
However, trainer Paul Nicholls has taken Benvolio out of the extended four-mile heat due to the going.
With Nicholls making an early decision regarding Benvolio, it means the first reserve, Sue Smith's Vintage Star, gets to take his chance.
The champion trainer is still represented by the top weight Sam Winner, ridden by Sam Twiston-Davies.
He brings a touch of class to proceedings having run well in Grade One company in Ireland earlier in the season.
The English handler is hoping for a similar scenario to Many Clouds, who ran below expectations in the Gold Cup but bounced back to win the Grand National at Aintree last week.
"Sam Winner ran a bit flat in the Gold Cup, but then so did horses like Many Clouds and Silviniaco Conti and they've come out and won since," said Nicholls.
"On his best form, when he beat the likes of The Druids Nephew at Cheltenham giving him weight and finishing third in the Lexus, he'd definitely have a chance.
"He's fairly versatile ground-wise."