Australian Nick Kyrgios has had to issue a “stop calling me” plea after Stefanos Tsitsipas played a prank on him for a surprise 25th birthday gift.

Tsitsipas posted his phone number on instagram in an image of himself holding a cardboard sign captioned “Lift others up” with a phone number featuring an Australian code.

The number turned out to belong to Kyrgios.

Fans realised that it was Kyrgios’ number and the Australian star said: “You are an absolute idiot, everyone stop calling me!!!!!”

Kyrgios said he was overwhelmed by the calls: “What’s up guys, I understand it’s my 25th birthday, but please I understand that Tsitsipas posted my number on his Instagram,” he said on his Instagram story.

“Please stop calling me, I can’t even play music, can’t do anything. Please stop calling my cell phone.”

The pair became friends while on tour, after Kyrgios defended Tsitsipas when the Greek star was scrutinised after an outburst during Australia’s ATP clash against Greece in January.

The number has since been disconnected.

Tsitsipas has launched ‘Beyond 100 Support’, an auction for to raise money for a player relief programme to provide assistance to players who are financially affected but the coronavirus crisis.

“As the youngest player in the Top 10, I feel responsible to help the future of tennis. I understand how critical it is for the sustainability of both ATP and WTA players ranked beyond the Top 100 and how difficult it is to make a living from professional tennis, especially with no tennis events going on for an undefined period of time,” Tsitsipas said.

“Through the creation of ‘Beyond 100 Support’, I hope to start a movement that my fellow players will follow suit.”