Novak Djokovic lauded the bravery of Andy Murray as he expressed compassion for the three-time grand slam champion following his retirement revelation.

Murray wants to retire at Wimbledon but the former world number one could walk away from tennis after the Australian Open due an ongoing hip injury.

Tributes have poured in for the 31-year-old Brit, who has won two Wimbledon crowns and the US Open, as the curtain prepares to come down on his career.

And 14-time major winner Djokovic hailed Murray in an Instagram post on the eve of the Australian Open in Melbourne.

Djokovic – who is favourite to reign supreme at Melbourne Park – wrote on Sunday: "Tarbes, France 2001… 'Les Petite As'. First time we met and played."

"Something was telling me back then that we would have an amazing rivalry and experience of playing each other on the biggest stage for many years to come." 

"What you are trying to do is nothing short of brave and inspiring. I met with you the other day and couldn't really verbalise my compassion for what you're going through."

"As an athlete, fellow tennis player and friend, I respect and fully support you every second of this Australian Open and every next attempt to compete at the highest level."

"Whatever happens, I will always cherish our amazing matches over the years and be grateful for those experiences Big hug Andy, stay strong. @andymurray."

Australian Open women's champion Caroline Wozniacki also paid tribute to Murray ahead of her title defence.

Wozniacki – who has been diagnosed with rheumatoid arthritis – told reporters: "I think it's sad, I'm sad on behalf of Andy because Andy is so fun for me to watch. I think he's entertaining. He's such a great athlete. He stood up for us, too. I really appreciate what he's done for women's tennis."

"I talked to him a little bit yesterday actually, ran into him at the hotel. It's never fun when it's not on your terms. He loves the game. You can tell how passionate he is about it."

"But I guess you can't do anything about it. That's sports sometimes. You can't help when your body says it's enough. Sometimes life is more important, although it seems hard at that time."