Novak Djokovic and Andy Murray have known each other for a quarter of a century. Yet they've never been able to talk shop and freely trade all sorts of thoughts — about tennis and otherwise — until now.

Novak Djokovic being coached by Andy Murray, plus Jack Draper in deciding set: latest from the Australian Open In a ding-dong game he pulls through to lead the decider 3-1.

On Thursday, Murray was sounded out for an interview after Djokovic went up against Alexander Zverev in an exhibition match. He joked that he would try to ruin the Serb's hopes of lifting the trophy as payback for his own failure to win the event.

If Novak Djokovic can win a 25th major title in the coming days, he will bolster his claim to be considered the greatest athlete in history, according to his new coach Sir Andy Murray.

The Serbian star, who has won the tournament 10 times, faces American Nishesh Basavareddy in the first round on Monday.

When Novak Djokovic rang Sir Andy Murray in the middle of a round of golf to ask the former No.1 to be his coach, the Serbian champion was very clear about why. “He wanted an opponent to coach him,” Murray says. “I was shocked, obviously. I had no interest in doing any coaching at that moment. I’d retired. I was really enjoying my home life.

The recently retired Andy Murray has teamed up with longtime rival Novak Djokovic as his coach. Here's what fans at the Australian Open think about the pair.

"Andy Murray over there on the sideline, I think was starting to get a little nervous with what was going on."

John McEnroe feels even Andy Murray was getting nervous for Novak Djokovic during his second-round match at the Australian Open after Jaime Faria took the second set. The 24-time Grand Slam champion has made a habit of being a slow starter at major tournaments in recent years.