Peter Bowen feels Sir Johnson is the forgotten horse of the Weatherbys Champion Bumper.
The six-year-old has won all four of his races, which takes a good deal of doing in the bumper sphere.
He also had Colin Tizzard's Royal Guardsman, subsequently an impressive winner at Ascot, over five lengths behind him on his latest start at Aintree in October.
While that one is a single-figure price next week, Sir Johnson can be backed at 20-1.
"Providing everything is fine between now and then he'll run next week," said Pembrokeshire-based Bowen.
"He's four from four in bumpers, and there aren't many that can do that.
"I took him away to Newbury for a gallop the other day and he worked excellent.
"He's just been forgotten about because he hasn't run for a while, but I had no chance to run him."
Both Sir Johnson and Royal Guardsman were among 25 remaining entries at the confirmation stage.
Ante-post favourite Champagne Fever is one of four trained by Willie Mullins, along with Mozoltov, Pique Sous and The Paparrazi Kid.
Others prominent in the ante-post market to have stood their ground are Moscow Mannon, New Year's Eve, The New One and Village Vic - although Noel Meade has taken out Fickle Fortune.
Clonbanan Lad, who floored Mozoltov by 12 lengths at Naas, is not certain to take his chance, according to his trainer Michael O'Connor.
"It's 50-50 whether we go or not," O'Connor told At The Races.
"The owner (Edward Walsh) is in Italy at the moment and he doesn't know if he'll back for Cheltenham.
"I don't really want to go with the horse unless he can be there."
Sunday Indo Living