The highly-rated Monsignor heads a top-class field of 16 novices entered for the Sun 'King Of The Punters' Tolworth Hurdle at Sandown Park on Saturday.
The extended two-mile event looks sure to be one of the most significant pointers to the Cheltenham Festival run to date if all the principals stand their ground.
Monsignor, winner of the Weatherbys Champion Bumper at the Cheltenham Festival last March, is unbeaten in two starts over hurdles this term, including a defeat of another Tolworth entry Dusk Duel at Ascot last time.
Monsignor's trainer Mark Pitman said: "It looks a good race. We've never had the horse in better shape and the plan is to run on Saturday and it will be his last run over two miles _ probably.
"We've been looking to step him up in trip and I think that after this race we probably will do. He may well go for the River Don Novices' Hurdle at Doncaster on the 29th.
"We're taking things one race at a time. He's in exceptionally good form and we'll have a look and see what the race throws up.
"I do feel the horse has improved, he's come on with each run. He's absolutely bouncing and I think that whatever beats him on Saturday will have to be a very useful animal."
Dusk Duel's stablemate Mister Banjo, an impressive winner of the Finale Junior Hurdle at Chepstow over Christmas, could be in the opposition.
Henderson said: "He's come out of the Finale Hurdle in fine form and there's a 60-40 chance of him running in the Tolworth as I've always said I wanted to give him a couple more outings before Cheltenham for the experience.
"I talked to David Minton and Anthony Bromley who run the Million in Mind Syndicate, which owns the horse, and as a result he's entered for the race and we'll make up our minds whether he runs later in the week.
"But four-year-olds have won the race plenty of times in the past and as they get a big weight allowance we are very much looking at Sandown as a possibility for him."
This race has long been the mid-season target for Ballinclay King, an impressive winner twice this campaign for trainer Ferdy Murphy.
"He won at Ayr and Haydock on his first two starts and has done all we've asked of him," Murphy said.
"He goes to Sandown for the Tolworth Hurdle at the weekend and then it's up to him to prove that he's up to running in the Royal & SunAlliance Hurdle _ I think he is.
"The only hiccup came last season in the Punchestown bumper but I still think he ran a great race to finish fourth. I think he'd be better in a true-run race."
Smart Flat recruit Clifton Fox, an impressive winner on his hurdling debut at Newcastle in December, is another possibility for the race.
The gelding's trainer Jonjo O'Neill said: "I'd put him a handicap at Taunton on Thursday but he's very unlikely to go there.
"I have put him in the Tolworth Hurdle at Sandown on Saturday but it is only a possibilty at the moment. We'll have to have a look and see what's in it.
"He came out of the Newcastle race all right and I suppose goodish ground will suit him."
Also in the field are the Paul Nicholls-trained Ask The Natives, an impressive winner of both his starts this campaign, and Francois Doumen's Snow Drop.
Baronet, the 1998 Scottish Grand National winner, is among 12 horses entered for the Coral Mildmay Cazalet Memorial Chase on the same card.
Possible rivals to Alan King's charge include the Sue Smith-trained The Last Fling, winner of the Bet Direct Edward Hanmer Memorial Limited Handicap Chase at Haydock in November, and Sounds Like Fun, third for Henrietta Knight behind Tresor De Mai in the Tote Silver Cup Chase at Ascot last month.
