The giant five-year-old lost his unbeaten record in the Tolworth Hurdle last time out, but emerged with his reputation enhanced.
Murphy's father, Paul, owns Kalashnikov and insists there is no pressure at all on running him at Cheltenham, where he is around 16-1 for the Supreme and Ballymore Novices' Hurdles.
"We've decided to go for the Betfair," said the owner.
"It's worth more money than the Cheltenham races for a start and I prefer Newbury as a track.
"It would be a bigger field at Cheltenham, he could get brought down or anything.
"I'm not saying he won't then go to Cheltenham, but he'll also have Aintree as an option, too. We'll see how he gets on at Newbury first."
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