Jamie Moore is set to be reunited with Ar Mad in theBerkshire Community Foundation Clarence House Chase at Ascot.
The Gary Moore-trained seven-year-old won four successive races as a novice last season, but missed the spring Festivals due to injury.
He made a promising return to action when fourth in the Tingle Creek at Sandown last month, after cutting out much of the running.
Joshua Moore has partnered Ar Mad on his last five starts, but as he is now sidelined, his brother Jamie, who has teamed up with the horse on four previous occasions,is set to come in for the ride on Saturday week.
"With Josh on the sidelines, Jamie will ride Ar Mad," the trainer said in his Betway blog.
Moore reports Ar Mad to be firing on all cylinders ahead of his rematch with Tingle Creek hero Un De Sceaux.
Stable stalwart Sire De Grugy, who was runner-up in the Tingle Creek, is set to bypass in the Clarence House Chase in favour of an appearance at Newbury next month.
Moore said: "I t is looking more and more likely that Ar Mad will be our only runner in the race,
"He seems a different horse now from the one going into the Tingle Creek and is flying at home.
"Maybe Un De Sceaux has improved plenty since, too, but I honestly couldn't be more delighted with Ar Mad.
" Sire De Grugy is in great form at home, too, but I'm just leaning towards giving him a bit more of a break as he's been busy.
"The other factor is jockey bookings. I'dhave to put someone else up on Sire De Grugy and I'm not all that keen on doing that.
"The Clarence House will tell us whether Ar Mad is a genuine Champion Chase contender or whether or not we elect to step him up in trip for a race like the Ryanair Chase.
"Win, lose or draw at Ascot, I have half an eye on going back to Ascot with him again in February for the Ascot Chase."
On Sire De Grugy, the trainer added: " A week is a long time in racing, but at the moment my preference is to wait for the Game Spirit, where he could be joined by Traffic Fluide.
"I've been delighted with Traffic Fluide's progress and he is getting there every day. If I can, I'd like to get a racecourse gallop into him somewhere before Newbury."