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"The best one-handed backhand in the game." That's how John McEnroe has described Stan Wawrinka's signature stroke. High praise indeed. So one would imagine that allowing Wawrinka little opportunity to use that potent weapon is high in the Djokovic tactical masterplan.

"I changed my backhand from two-hander to one-hander at 11 years old with my first coach, Dimitri," the 30-year-old Swiss told BBC Sport last year.

"He asked me to try as for him it was more natural to play one-handed, but it was difficult for me at 11 to play one-handed because you don't have that much power.

"It's not easy, but Dmitri was always behind me, saying: 'It's going to take time but it's going to be better in the end'. And he was right."