Last season’s brilliant Arkle Trophy winner Un De Sceaux was due to be the headline act in Esher before being ruled out by Willie Mullins on Wednesday after being described as a “little flat”, prompting a major overhaul in the betting.
Simonsig, winner of the Arkle in 2013, looked in with a major chance of keeping his unbeaten record intact following a most encouraging return to action from over two years off when runner-up behind stable companion Bobs Worth in a hurdle race at Aintree last month.
But he too will now be on the sidelines after suffering a late setback.
Henderson said: “Simonsig is not running tomorrow, he’s lame.
“He was OK this morning, Barry (Geraghty) came in and rode him and he schooled, but unfortunately he is lame tonight.
“I honestly don’t know why, it is so, so cruel. I’m desperately sorry for Ronnie (Bartlett, owner), he has waited over two years to get him here.
“He schooled this morning and he was fine. It’s horrible, especially given we had got a prep run into him that had gone so well.”
Henderson will still be represented by Josses Hill, who did not always convince in the jumping department last season but ran a fine race to finish third behind Un De Sceaux at Cheltenham.
Barry Geraghty, due to ride Simonsig, will now partner Mr Mole for his boss JP McManus and trainer Paul Nicholls.
Nicholls has an incredible record in the Grade One event and Mr Mole is one of two runners bidding to give him an eighth success in the past 11 years.
He perhaps holds stronger claims with the likely favourite and Haldon Gold Cup hero Vibrato Valtat.
Nicholls told Racing UK: “Mr Mole is in no-man’s land at the moment. It’s tough for him in Grade Ones but he’s handicapped out of things so where else do you go?
“We’re hopeful of a good run. He’s won at Sandown a couple of times so he’s an outsider on what he’s done, but the other one (Vibrato Valtat) deserves to be favourite on what he’s done.
“Vibrato won the Haldon Gold Cup, which is a good stepping stone for this.
“We’re hoping he’s an improving horse and he should have a good chance.”
Sire De Grugy, who won the Tingle Creek two years ago, has lost his sparkle of late and trainer Gary Moore admits he is close to entering last-chance saloon against the very best.
“He’s got his work cut out,” said the West Sussex hander.
“I didn’t feel he got back on track at Exeter (last of five behind Vibrato Valtat).
“He launched himself at the first ditch again, which was disappointing as we’d done a lot of work with him – I hope he doesn’t do it again.
“The only saving grace was that he was still there at the second-last but he didn’t finish his race off like I’d have liked to have seen him do.
“Jamie (Moore) said he wasn’t fit, but I can’t believe that. That was his theory, though, I just can’t believe that.
“He’ll be fitter on Saturday, but he’ll need to be.”
Mick Channon has booked Nina Carberry for Somersby, runner-up in the Tingle Creek in the last renewals, after the pair teamed up to win with Knock House at Cheltenham.
“He loves it there and the old boy is in great form,” said Channon.
“He was also entered at Huntingdon, but that was a hot enough race as well and there was also the trip to think about.
“It looks like it’s going to be decent ground, but he goes on anything so that won’t really matter to him.”
Irish hopes rest with Henry de Bromhead’s well-backed Special Tiara, winner of the Celebration Chase over this course and distance in April but tailed-off on his reappearance in the Fortria Chase.
Owner Sally Rowley-Williams said: “He wasn’t 100 per cent the last time he ran.
“It absolutely poured down so he hated the ground, anyway, but when he returned we found out he just wasn’t quite right. Noel (Fehily) is such a great horseman and they seem to suit each other down to the ground.
“As Special Tiara is such a fluent jumper he doesn’t need much instruction and Noel lets him get on with it.
“The fact Un De Sceaux isn’t running might mean we get an easy lead, but even though people say we have to lead that’s not true.
“He didn’t make all (the running) at Sandown, and when he won his Grade One as a novice at Aintree, Bryan Cooper realised Overturn wanted to lead so he let him go on. It’s more important he gets into a rhythm with his jumping than leading, and that is normally a case of if the ground is too soft or not.”
Colin Tizzard’s consistent but difficult-to-win-with Third Intention completes the line-up.
2-1 Vibrato Valtat, 7-2 Special Tiara, 5-1 Sire De Grugy, 7-1 Somersby, 8-1 Josses Hill, 12-1 Mr Mole, 18-1 Third Intention.