The eight-year-old’s trainer Willie Mullins and owner Rich Ricci had indicated they might avoid a clash with their other hope, Min, in Wednesday’s big race and wait for Thursday’s Ryanair Chase.
But Douvan is one of nine horses declared for the two-mile championship, and Mullins said: “We discussed things last night.
“Ruby [Walsh] has been very happy with Douvan in recent days and was keen to ride him in the Champion Chase rather than in the Ryanair.
“That made my mind up where to run him and Rich Ricci was happy with that.”
Douvan has been out of action since disappointing in this race 12 months ago, when sent off the 2-9 favourite.
Mullins’ other contender Min heads to Prestbury Park on the back of an emphatic victory in the Dublin Chase at Leopardstown last month.
The seven-year-old has a score to settle with bookies’ favourite Altior, having been beaten seven lengths when they met in the Supreme in 2016.
Altior has been declared but is a doubt ahead of the race after suffering an injury scare.
Trainer Nicky Henderson said: “Altior was unfortunately lame this morning in his near fore leg and we have located some puss in the frog (of his foot.
“He was still able to exercise in the water treadmill this morning, which he regularly does anyway, and a poultice will now be applied and left on overnight to draw out the puss.
“The foot will also be tubbed (stood in salt water) at regular intervals and the show will hopefully be replaced first thing tomorrow morning.
“Both our vet and farrier are working very hard and are more than hopeful that he will even be able to canter tomorrow and therefore confident he will be clear t race on Wednesday.
“Obviously we will monitor the situation and keep everybody up to date with his progress but there will be nothing more to say until tomorrow morning.”
Altior is evens favourites to win the Grade 1 race while and Douvan and Min can be backed at 11/4 and 3/1 respectively.
Last year’s winner Special Tiara will hope to defend his crown while Paul Nicholls’ Politologue is also confirmed.
Ordinary World, Ar Mad, Gods Own and Charbel complete the field.
The only withdrawal at the 48-hour final declaration stage was the Mullins-trained Un De Sceaux, who is set for the Ryanair Chase.
