There have been theories thrown out there as to why Djokovic made his coaching decision, but seven-time major champion John McEnroe offered a pretty hilarious theory this weekend.

John McEnroe has joked that Andy Murray agreed to coach Novak Djokovic so he can discover ways to beat the Serbian. The American teased that Murray would then come out of retirement and use the knowledge to get the better of the 24-time Grand Slam champion in a showdown on the court.

Novak Djokovic and Andy Murray have known each other for a quarter of a century. They played from the age of 12, meeting 36 times as professionals, including 10 Grand Slam matches.

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.

And Murray is confident more major silverware will follow for Novak Djokovic, who he thinks can establish himself as the best athlete of all time

If Novak Djokovic Wins Australian Open, Andy Murray Would Be ‘Flooded With Coaching Requests,’ John McEnroe Says

It will be all business when Andy Murray coaches Novak Djokovic at the Australian Open. While the partnership between two of the biggest rivals in recent men’s tennis history has awakened feelings of shock,

John McEnroe saw the funny side of Andy Murray joining Novak Djokovic's coaching team, floating the idea of Murray returning with fresh knowledge of his rival.

Novak Djokovic is currently preparing for the Australian Open, where he will bid to win a record-breaking 25th Grand Slam title.

John McEnroe believes Andy Murray could come out of retirement once he's done working with Novak Djokovic at the Australian Open. The tennis legend hung up his racket back in the summer after playing doubles with Dan Evans at the Paris Olympics.