Novak Djokovic and Daniil Medvedev have criticised Olympic organisers and called for tennis matches to be played later in the day to avoid having to play in the sweltering conditions. Both players began their campaign with straight sets wins and are seen as the leading contenders to win gold in the men’s singles.

Djokovic breezed past Bolivia’s Hugo Dellin in straight sets but was far from happy with playing in the hot and humid daytime conditions in the Japanese capital.

He said that players were “constantly dehydrated” from having to play during the day.

Temperatures reached 32C at one point during play at the Ariake Tennis Park.

The world No 1 said: “I don’t understand why they don’t start matches at, say, 3pm.

“We still have seven hours to play. They have lights on all the courts.”

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The Serb has often struggled to play in hot conditions but he is far from the only one to complain at this years event. 

No 2 seed Medvedev was also unhappy with the playing conditions after his win over Alexander Bublik.

“I don’t think they are going to change anything in the middle of the tournament but that’s what can be done,” he said.

“I think the fact that we have only one minute between the changeovers is a joke. It should be 1:30, like it is in other tournaments.”

A statement released by the ITF said: “Great consideration has been given to the 11am or later start. 

“The decision to retain 11am was made based on data, a nine-day event and to accommodate factors such as local authority restrictions due to Covid-19 and the unpredictability of the weather.

“Extreme conditions will always put pressure on a schedule and make an optimum schedule challenging.

“Rainfall is as much of an issue as extreme heat. An Extreme Weather Policy is in place.

“Tokyo 2020 competition officials have set procedures to monitor the heat stress index which determines whether play should be modified and have implemented these procedures today.”