Nishikori tells Asian players to muscle up

London : Asian players need to work on their strength in the gym in order to mix it with the big hitters on the tour, said Japan's world number six Kei Nishikori.

The best Asian player currently in the sport said that enhanced physical resilience needed to be matched with rock-solid self-belief to hang in there with the best in tennis.

Nishikori on Saturday booked his place in the last 16 at Wimbledon, where he will face ninth seed Marin Cilic in a repeat of the 2014 US Open final won by the big-serving Croat.

"First of all, you have to be really strong. Especially if you are Asian, you have to do a lot of training in the gym," said Nishikori.

"Physically you have to be strong. Otherwise, like me, I got a lot of injuries in the past playing against those big guys with a lot of power.

"I've been spending a lot of time in the gym. Also mentally you have to be really strong, believe in yourself. It's not easy for most Asian people, body‑wise.

"Like me, or David Ferrer, he's very physically strong. When you believe in yourself, I think you can be top 10, whoever you are."

Nishikori earned his place in the Wimbledon fourth round with a 7-5, 6-3, 7-5 win over Russia's Andrey Kuznetsov on Saturday and is feeling in good form.

"At certain moments I was playing aggressive. He can be a really tough player, especially here.

"He hits very flat. Especially in the third set, he started playing much better, playing more aggressive," the 26-year-old said.

"It was a tough third set. But I tried to be a little bit more aggressive, took a little bit of time with changing with the slice. The serve, too, I changed a little bit. It started working better.

"I think I played one of the best games today."

Nishikori has made the quarter-finals at the three other Grand Slams but never at the All England Club, in seven previous attempts.

He pulled out of Wimbledon last year due to a leg injury.

In reaching the fourth round, he matched his best performance at the All England Club, achieved two years ago.