Mick Channon's Cheltenham Festival winner has been left on 11-3, with the weights going up 4lb following the defection of Thistlecrack, and he's Sky Bet's 6/1 joint-favourite.
Mister Whitaker is set to renew rivalry with the Nicky Henderson-trained Rather Be (fellow 6/1 fav), who went down by just a head in the Close Brothers' Novices' Handicap Chase at Cheltenham in March.
"Everything has been good, he's got one more bit of work to do," said Henderson.
"He just took a little bit of time to come to hand, but he's in good shape now - his work last weekend was very good.
"His run at Cheltenham was very good, that race (Close Brothers Novices' Handicap) is a real conundrum, you've got to have three runs, you can't go over 145 but if you're 140 you run the risk of not getting in.
"I've got three horses that are on that rating now, so I've got to hold them there between now and next March. Two and a half miles around there is just about perfect and good ground will suit him.
"He's progressed every year, so let's hope he can keep it up. His last two bits of work have been very good, so I think the bloom is there."
Frodon was raised 3lb in the ratings for his comeback win under Bryony Frost in the Old Roan Chase at Aintree, and he heads a four-strong team from Paul Nicholls yard in the Grade Three event over two and a half miles.
The six-year-old could be joined by stablemates Le Prezien, Movewiththetimes and Romain De Senam as Nicholls seeks a third victory in the race. His two previous winners were Al Ferof (2012) and Caid Du Berlais (2014).
Baron Alco is the sole representative for Gary Moore, while local trainer Nigel Twiston-Davies could run three including Splash Of Ginge, who returns for another crack having won the race last year. Crievehill, and Ballyandy are others in the mix for the Twiston-Davies team.
Colin Tizzard could rely on Sizing Granite and West Approach, while David Pipe also has a couple of strings to his bow with Eamon An Cnoic and the lightly-raced King's Socks.
Other possibles at this stage include Guitar Pete for Nicky Richards, Alan King's Full Glass and Emma Lavelle's Javert. Black Scorpion is the sole Irish contender.
