World No.1 Novak Djokovic said he initially struggled to cope with the uncertainty surrounding when tennis can restart after its shutdown in early March due to the novel coronavirus.

The sport is suspended till at least mid July due to the virus, which has infected more than 3.19 million people and killed almost 227,000,

“For us tennis players it is important that the calendar is clear,” Djokovic told Sky Sport Italia.

“Officially it is the 13th of July, many people say it is difficult we will start again on that day.

“For me it is important to have a routine, I cannot keep on waiting for that day. I train every day at the gym, I run at home, I play with my kids and this is also hard work.

“At the beginning I was mentally a bit empty and confused, because (the timing) wasn’t clear. I talked with my team, I tried to train every day, even though I didn’t follow the preparation strictly.”

Djokovic was in imperious form before the circuit came to a halt.

The Serb lifted the ATP Cup with Serbia, won a record-extending eighth Australian Open title in Melbourne and then completed a fifth triumph at the Dubai Tennis Championships, extending his unbeaten run to 21.

The virus has forced the cancellation of this year’s Wimbledon for the first time since World War Two while the French Open was rescheduled for September 20 – October 4, shortly after the end of the US Open.

“Officially it (the restart) is the 13th of July but the WTA in Canada (Rogers Cup) has already been cancelled, although not the men’s event,” Djokovic said.

“We need to see how the situation in the United States goes, because we are expected to go there in August.

“There’s the possibility that they cancel all the events in America and that we go back to the tennis court in Autumn, maybe we can go to Rome in two-three months… let’s hope we can get back to playing.”