Holger Rune says consistency within his return game is a large part of what makes Novak Djokovic such a tough opponent to play.
Rune played Djokovic for the first time at the US Open on Tuesday and he managed to take a set off the world number one before suffering from severe cramp.
Djokovic went on to easily win as Rune's mobility deteriorated, but the 18-year-old had seen enough to know what makes the Serbian so good.
"I think [Djokovic] is incredibly consistent, he never gives you anything," Rune said. "You have to really win every point by yourself.
“Especially behind your serve, you know you have to really put every first serve [in].
"Otherwise, he’s stepping in on the baseline and really putting you under pressure and that’s just a huge pressure, you know.
"You really want to hold your serve, because, you know, if he hits his spot – it’s tough to break him.
"And you know, he’s just a tough player to play. But I’m not saying if I was physically 100% I would beat him for sure – but I would definitely have a chance."
Djokovic is attempting to complete the Calendar Slam at the US Open having already won the Australian Open, Roland Garros, and Wimbledon this year.
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