Boris Becker said Novak Djokovic approached him to become his head coach the day the Serb lost the world number one ranking to Spaniard Rafael Nadal in October this year.

Djokovic’s announcement last week that the German six-times grand slam champion was to become his coach was greeted with surprise and Becker himself said it had been unexpected.

“I was approached by Novak and his manager while he was playing in Beijing,” Becker said.

“He decided he needed somebody in his corner that had been there and done it. I was surprised – I didn’t expect the phone call. I was very honoured.”

Marian Vajda, who has been 26-year-old Djokovic’s coach for each of his six grand slam titles, will continue as part of the team but Becker is set to assume head coach responsibilities at the forthcoming Australian Open which starts on January 13.

It will be Becker’s first foray into coaching top-level.

“This isn’t a half-hearted job, it wouldn’t be right for him or for me,” Becker said. “You’re in it to win it. You either go at it fully or you don’t.”