The seven-year-old had been well supported after Barry Geraghty was booked for the ride, but trainer Mouse Morris has revealed he will now miss out.
“I had to make a final decision this morning and I just wasn’t 100% happy with him,” said Morris.
“He would have had to travel today and I wasn’t happy for him to do that.
“It’s not a season-ending injury or anything like that, he’s just going to have to miss this one.
“I hope he’ll be all right to run at Christmas, probably in the Lexus Chase at Leopardstown.”
Sam Thomas is counting down the hours until he will be reunited with Denman as he seeks a historic third win in the prestigious handicap.
Thomas expressed delight after having schooled his big-race mount at Paul Nicholls’ Ditcheat yard on Wednesday morning.
“Obviously I’m over the moon and delighted to be back on a horse who has done so much for my career,” said Thomas.
“He’s in good form and hopefully he’s come back to something like his best.
“I go down there quite often and sat on him last Monday when we had a scoot round Wincanton racecourse which was fantastic.
“We do get on well – I find it very easy to ride a horse like him. At times you’re like a passenger. I leave it up to him and that’s the way he likes it.
“There’s no pressure. we know what we have to do, our cards are on the table and we’re the ones to be shot at.
“Denman is up in the weights but he doesn’t know that. He’s been top weight throughout his career and it’s not a problem.”
Lucinda Russell, meanwhile, is expecting big things from Silver By Nature - even though conditions might not be ideal.
The trainer told Racing UK: “He’s better on heavy ground but he’s got the class to cope with it.
“He’s really straight. We’re only going to have a few races this season so we’ve got to get it right in each one.
“He’s got a great chance and there’s not a huge amount of pressure on him.”
Colin Tizzard is in confident mood as he prepares to saddle recent Carlisle winner Hey Big Spender.
The seven-year-old edged out fellow Hennessy aspirant Big Fella Thanks in Cumbria, and his trainer is delighted to have secured the services of Aidan Coleman to ride him this weekend.
“He came out of the Carlisle race lovely. We’ve had him in the school and Aidan came and rode a piece of work on him on Tuesday and everything went fine.”