Amy Murphy's Grade One-winning chaser will undergo a series of tests this week, after breaking a blood vessel as he trailed home last of five finishers behind Altior in Saturday's Game Spirit Chase at Newbury.
ALTIOR regains the winning thread in the Win Bigger On The @BetfairExchange Chase at @NewburyRacing, picking up well in the closing stages to settle the contest!— Timeform (@Timeform) February 8, 2020
Will he make it three Champion Chase's on the bounce next month?
That was a second successive disappointing performance from the seven-year-old, who has previously been notably consistent.
His trainer is therefore determined to get to the bottom of the problems, and will ensure an extensive break until next season if necessary.
But Murphy is wary of calling time on Kalashnikov's campaign just yet, in case there is a chance of him returning to the scene of his finest hour to date - at Aintree in April.
"In himself, he's absolutely fine," she said on Sunday morning.
"But obviously he's just going to need a bit of time off now.
"He's bled twice in a short space of time, and realistically Cheltenham is going to be off the cards."
Kalashnikov won at Grade One level as a novice at Aintree last year, and the Grand National meeting stages the Melling Chase over the same distance of two and a half miles.
Murphy added: "If he came good and he was 110 per cent pre-Aintree, then we might look at it.
"Otherwise, equally, he doesn't have to run again and we can bring him back next season.
"He's going to go into Newmarket Equine Hospital on Monday morning and have a full MOT, just to check there's nothing underlying that's causing him to do it.
"I suppose by the end of next week we'll either have found something or found nothing - and it'll just be a case of time's a great healer."
It is therefore too early for her to confirm Kalashnikov's campaign is over.
"I don't want to write off Aintree, then suddenly we find something next week, we get it fixed - or it's something simple, like his wind," she said.
"So I don't want to write off the whole season, then be in a different place in six weeks' time."