Novak Djokovic dramatically retired from his Australian Open semi-final to a chorus of boos from sections of the Rod Laver Arena crowd as opponent Alexander Zverev called for “respect” to be shown to the 10-time champion.

Djokovic immediately shook hands with Zverev upon losing the first-set tiebreak after struggling with a torn muscle in his upper left leg, sustained in his quarter-final comeback over third seed Carlos Alcaraz on Tuesday.

There were a few jeers from the crowd as the match ended far earlier than expected and the 37-year-old, who was bidding to become the oldest grand slam champion of all time in Melbourne, held his thumbs up as he departed the court.

Djokovic later admitted there was a chance that he would have played on if he won the first set but, with 82 minutes already on the clock, the Serbian said he did not have anything left in the tank to come from behind once again.

As Zverev was left on court having reached his first Australian Open final, the German second seed praised Djokovic and called for the crowd to be more “respectful” towards the 24-time grand slam champion, who later raised doubts over whether he would return in 2026.

“The very first thing I want to say is please don’t boo a player when he goes out injured,” said Zverev, who was forced to retire from a French Open semi-final against Rafael Nadal after tearing ankle ligaments three years ago.

“I know that everybody paid for tickets  and wants to see a five-set match but you have got to understand Novak Djokovic is somebody that has given this sport for the past 20 years absolutely everything in his life.

“He has won his tournament with an abdominal tear, won this tournament with a hamstring tear, if he feels he cannot continue a tennis match, he cannot continue a tennis match. So please guys, be respectful. Show some love for Novak as well.”

Djokovic played through a torn hamstring injury to win the Australian Open two years ago but said the pain was different this time.

He admitted after beating Alcaraz that he would have considered retiring from the match if he had lost the second set and was unable to face coming from behind to beat Zverev.

“I didn’t hit a ball since the Alcaraz match, so until like an hour before today’s match,” he said. “I did everything I possibly can to basically manage the muscle tear that I had, medications and the strap, and the physio work helped to some extent today.

“But towards the end of that first set I just started feeling more and more pain. It was too much, I guess, to handle for me at the moment. Unfortunate ending, but I tried.

“If I won the first set, maybe I would try a few more games, half a set, maybe a set. I don’t know. It was getting worse and worse.

“I knew even if I won the first set, that it’s going to be a huge uphill battle for me to stay physically fit enough to stay with him in the rallies, you know, for another God knows what, two, three, four hours. Unfortunately I don’t think I had that today in the tank.”

Djokovic admitted there is a “chance” he has played at the Australian Open for the final time but insisted he remains motivated to chase further titles.

Injuries are now becoming a major barrier to Djokovic’s goal of winning a record 25th grand slam title, with last season’s French Open run also halted prematurely when he sustained damage to his knee ligaments.

“How much of a worry is it? I don’t know. It’s not like I’m worrying about approaching every grand slam now whether I’m going to get injured or not, but statistics are against me in a way in the last couple of years,” Djokovic said.

“But I’ll keep going. I’ll keep striving to win more slams. And as long as I feel that I want to put up with all of this, I’ll be around.”

Djokovic also said he and Andy Murray would discuss their future together injury brought their coaching agreement to an abrupt end.

Djokovic shocked the tennis world last year when appointed former rival Murray as his coach on a short-term agreement through to the end of the Australian Open.

Murray admitted the offer took him by surprise after telling friends that he did not plan on turning to coaching following his retirement from the game.

But Djokovic said he would only have “positive” feedback for Murray, and praised his impact following the quarter-final win over his young rival Alcaraz.

“I’ll definitely have a chat with Andy and thank him for being here with me,” Djokovic said. “We are still hot-headed and disappointed, so it’s kind of hard to switch the page and start talking about what the next steps are. I think we both need to cool off a little bit and then we’ll have a chat.”

Murray remained tight-lipped, however, telling reporters in Melbourne: "Me and Novak agreed that after the tournament we would speak. We'll do that."

Meanwhile, Zverev will face defending champion Jannik Sinner in Sunday’s final after the World No 1 brushed aside Ben Shelton in straight-sets to set up the chance of back-to-back titles in Melbourne.

Sinner won his first grand slam at the Australian Open 12 months ago when he came from two sets down to defeat Daniil Medvedev and the Italian has since underlined his status as the best player in the world.

The 27-year-old Zverev holds the advantage of playing for just over an hour against Djokovic, while Sinner needed much longer to defeat Shelton 7-6 6-2 6-2 and was struggling with cramp as the match finished after midnight local time.

Zverev has his demons in grand slam finals, though, losing the US Open final from two sets up to Dominic Thiem in 2020 and the French Open final from two sets to one up against Carlos Alcaraz last June.

And Djokovic declared that he would like to see the German make his grand slam breakthrough. “I wish Sascha all the best,” Djokovic said. “He deserves his first slam. I’ll be cheering for him. Hopefully he can get it.”

Sinner is on a 20-match winning run at the hard-court grand slams having won the Australian Open and US Open titles last season and now reaching a third major final.

But the last player to beat Sinner at either the Australian Open or US Open was Zverev, after the German won a five-setter at Flushing Meadows in 2023. Zverev has also won four of the six matches he has played against Sinner.

“Very tough match,” Sinner said when looking ahead to the final. “We had some very tough matches in the past. He is an incredible player and is looking for his first major. There is going to be a lot of tension but I’m happy to put myself in this position. I’m going to enjoy it.”