Barry Geraghty has been formally booked to partner Diamond Harry in the William Hill King George VI Chase at Kempton on St Stephen's Day, where all eight confirmed entries have been declared to run.
Geraghty, who landed the Christmas highlight in 2004 and 2005 aboard Kicking King, steps in for the plum spare ride on the Nick Williams-trained eight-year-old, owned by the Paul Duffy Diamond Partnership and winner of last season's Hennessy Gold Cup.
He was last seen in the Betfair Chase where he was ridden by James Reveley, who will be in action at Wetherby.
Paul Nicholls' four-time winner Kauto Star has been declared alongside stablemate Master Minded while Nicky Henderson's Long Run, hero of the race last season as well as the Cheltenham Gold Cup, is all set for the rematch.
Paddy Brennan has been booked to partner Tom George's Nacarat and the other three contenders - Captain Chris, Somersby and Golan Way - all stand their ground at the final stage.
Ruby Walsh knows Kauto Star better than anyone, having ridden the majestic 11-year-old in each of his King George victories as well as his two Gold Cups.
The Kildare man also helped Kauto Star secure his historic fourth Betfair Chase at Haydock last month, when he pulled eight lengths clear of Long Run.
"Paul and I think he is probably better going the other way, but he has a great record at Kempton," said Walsh.
"Long Run is obviously going to improve and Paul had made no secret of the fact he had Kauto spot on (at Haydock). I'd imagine Nicky Henderson had bigger things in mind and he got caught on the day - he's the one we have to beat and he'll be sharper and fitter."
Walsh has also ridden Master Minded, the mount of Daryl Jacob, many times before and is not concerned the horse is stepping up to three miles for the first time.
"I don't see any issue with him staying, as he has got older he wants a trip," he told Racing UK.
"He settled well at Ascot and jumped super for Daryl, he'll get a great ride off him. I've ridden in a lot of King Georges, you either stay or you don't. You can't go round and hope you stay.
"I think Master Minded will stay and he has the pace to lay up. He maybe might have (stepped up in trip without Kauto Star in the same stable).
"He won a Champion Chase as a five-year-old, then went to Aintree and it looked like he didn't stay but maybe that was a race too far for a five-year-old."
Clive Smith appreciates he not only has one horse of a lifetime in Kauto Star, but two through Master Minded.
"We've always felt Master Minded might develop into a three-mile chaser and he's always been very good at two miles and two-and-a-half," Smith told At The Races.
"He's been developing all the time, while Kauto has been doing his stuff around the courses excellently, of course."
Smith is simply happy to be involved in such an occasion, despite the obvious pressure.
"It's a great racing moment and I'll enjoy it as much as I can," he said.
"Obviously I'm nervous about it because I'm nervous for their welfare, but I like thrilling races and I think this is going to be one. I'm sure Long Run will be there, but hopefully he'll come second to one of my two!
"I can't tell you how exciting it will be. I started owning horses 20-odd years ago and to be in this position is quite immense.
"I was down at Paul Nicholls' yard on Monday morning to see the horses and they were going off to do a bit of schooling.
"I felt how lucky I was walking behind these two magnificent horses. It was a great feeling."
