Imperial Commander heads a list of 49 horses left in the John Smith's Grand National at Aintree on Saturday following the five-day stage.
The 2010 Cheltenham Gold Cup hero could try to make up for missing another crack at last month's blue riband event with a minor infection.
His trainer Nigel Twiston-Davies, who has won the world's greatest steeplechase twice with Earth Summit (1998) and Bindaree (2002), has also left in Major Malarkey and Viking Blond.
The big guns at the head of the market have all stood their ground, headed by ante-post favourite On His Own.
His trainer Willie Mullins is also represented by Quel Esprit and Quiscover Fontaine as the champion Irish trainer looks to add to his success with Hedgehunter in 2005.
That horse's owner Trevor Hemmings also has Ballabriggs, the winner in 2011, who tries again. His trainer Donald McCain also has Weird Al, Across The Bay and Cloudy Lane, who is not certain to get a run.
The second, third and fourth home 12 months ago, Sunnyhillboy, Seabass and Cappa Bleu, are set to renew rivalry while other horses with proven Aintree form are 2011 runner-up Oscar Time, 2010 fourth Big Fella Thanks and triple Topham winner Always Waining.
Colbert Station, Teaforthree, Join Together and Chicago Grey are among the other fancied horses remaining in the line-up.
Further spice is added with Manchester United manager Sir Alex Ferguson having shares in both What A Friend and Harry The Viking, both trained by Paul Nicholls.
The eight horses to come out were Prince de Beauchene, Bob Lingo, Tofino Bay, Lion Na Bearnai, Bostons Angel, Beshabar, Wyck Hill and Magnanimity.
Lion Na Bearnai is out as he has picked up an infection that has been affecting Thomas Gibney's string.
The County Meath trainer had been facing a race against time to get last year's Irish National scorer ready for Aintree before the bug struck.
"There's a bit of a bug in the yard at the moment and he has it," said Gibney.
"He caught in last week and it hadn't gone according to plan before that. I couldn't afford to miss anymore time with him and everyday had to go right for the last three weeks to get there and didn't happen."
Gibney had also hoped to run Orpheus Valley in the John Smith's Topham Chase, but he too has gone down with the same problem.
"I also had a horse in the Topham on Friday and he scoped dirty this morning so he won't be going either," said the trainer.