Andy Murray winning the US Open could prove a turning point in his rivalry with Novak Djokovic, says former British number one Greg Rusedski.

Djokovic has won six of the last nine grand slams and also dominated his duels with the Scot, losing only twice in 15 meetings.

They arrive in New York, however, in very different veins of form, Murray on a high after winning Wimbledon and an Olympic gold medal, while Djokovic is struggling for fitness and confidence following early exits in both tournaments.

Murray opens up against the Czech Lukas Rosol on Tuesday as arguably favourite to clinch the title, but Rusedski believes there is more at stake than just silverware in Flushing Meadows.

"I think it'll be a battle between those guys for the next few years now and that's why this US Open is so intriguing," said Rusedski, who will be working for Eurosport during the tournament.

"Before Wimbledon it was like, just hand the trophy to Djokovic, but now it's shifted ever so fractionally and that's what makes it so exciting, because, if Murray wins, that's two majors apiece this year, which hasn't happened in a long while, and there could be a real shift of the guard happening.

"But then there's also a distinct argument that Djokovic is the greatest player of all time if he gets back to the streak he was on. I don't think he has a losing record against anyone on the planet, that shows just how good the guy is."

Djokovic and Murray appear to have pulled away from the traditional 'big four' as Roger Federer continues to nurse a knee injury and Rafael Nadal is without a grand slam semi-final since 2014.

Until Wimbledon, it was Djokovic who had capitalised most, but Rusedski feels Murray's moment may finally have arrived.

"You feel Andy maybe has the slight edge, but discount Djokovic at your peril," Rusedski said.

"He held all four majors at the same time going into Wimbledon, so he's a brilliant champion.

"But it does feel like this is Murray's time. If he's healthy and fit, it's his opportunity to take advantage and step up.

"Djokovic and Murray have separated themselves from the pack. It's not the 'big four', it's the 'big two' at the moment.

"Rafa has been struggling with injury, Roger struggling with injury, Stan Wawrinka hasn't got back to the levels he was at when he won the French and the Australian, so they've pulled ahead of those guys now."

Djokovic has admitted he is still suffering from the wrist injury that hampered him at the Olympics and there will be great interest in the top seed's early-round performances.

"It'll be interesting to see how Djokovic is first week," Rusedski added.

"It'll be defining how calm he is on court. He is usually so solid in those early rounds, it's that efficiency, confidence and calmness.

"If he has those things in the first week, the other players should start getting worried again."

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