Long Run and Kauto Star will clash for the third time in Saturday's Betfair Chase at Haydock.
The Nicky Henderson-trained Long Run emerged the victor in both the King George VI Chase at Kempton and the Cheltenham Gold Cup last term, with Kauto Star only third both times.
Donald McCain's Weird Al beat the Paul Webber-trained Time For Rupert by just over three lengths in the Charlie Hall Chase and that pair renew rivalries.
Diamond Harry was also supposed to run at Wetherby but was a late absentee after banging a leg in his stable. Nick Williams' charge will be returning from a long absence as he has not raced since winning the Hennessy Gold Cup 12 months ago.
Peter Bowen's Pure Faith has plenty to find on the ratings but split Albertas Run and Master Minded at Aintree when last seen.
James Reveley takes over from Daryl Jacob in the saddle on Diamond Harry having been appointed stable jockey to Williams in the summer.
"He's lightly-raced and has lots of ability. He's still really a second-season chaser because he had his novice year where he didn't run that often and then had just the one run in the Hennessy last year," Reveley told At The Races.
"Hopefully there's plenty of improvement in him, there'll need to be. He has every chance."
McCain's stable jockey Jason Maguire finally returns to the saddle on Thursday but he will not be riding Weird Al as he is needed to partner Overturn at Ascot, though he is sure to have one eye on the Haydock race.
He said: "He was a very good novice chaser and some reports have said he looked a bit delicate and his form tailed off last year. But he couldn't have been any more impressive a couple of weeks ago in the Charlie Hall, so we're hoping for a big run from him."
