Novak Djokovic said Friday there was a chance he may have played his last Australian Open after retiring with a muscle tear in the semi-finals to leave his bid for a record 25th Grand Slam crown in tatters.

The 37-year-old's upper left leg was again heavily taped after hurting it in the quarter-finals and the Serb called it quits after losing the first set 7-6 (7/5) to Alexander Zverev.

Djokovic left the court to a mixture of boos and applause as the German reached his first Melbourne final.

"There is a chance. Who knows," Djokovic said when asked if he may have graced the Melbourne Park courts for a last time.

"I'll just have to see how the season goes. I want to keep going. But whether I'm going to have a revised schedule or not for the next year, I'm not sure.

"I normally like to come to Australia to play. I've had the biggest success in my career here. So if I'm fit, healthy, motivated, I don't see a reason why I wouldn't come," he added.

"But there's always a chance, yeah."

Djokovic has now gone five Grand Slams without winning the title he needs to surpass Margaret Court's 24 and become the all-time leader.

He failed to collect one for the first time in seven years in 2024, with his last coming at the 2023 US Open, casting further doubt on whether he will ever get past Court.

His semi-final agony also deprived him of a 100th career title.

"I actually thought I played really well, as well as I played the last 12 months, to be honest," he said of his tournament run.

"I liked my chances if I was physically fit and ready to battle. I think I was striking the ball very well. A lot of positives to take in terms of how I played.

"I wish Sascha (Zverev) all the best. You know, he deserves his first Slam. I'll be cheering for him."

- Boos for Djokovic -

Zverev's reward is a clash in Sunday's showdown with either world number one Jannik Sinner or American 21st seed Ben Shelton.

While the German has been a Grand Slam runner-up twice before, at last year's French Open and the 2020 US Open, he has never before been to the final in Melbourne.

Last year at the same semi-final stage he crashed to Daniil Medvedev in five sets after holding a 2-0 lead.

But he came into the season with renewed vigour after ending 2024 as world number two, winning more matches than anyone bar Sinner and back to his best after a horrific ankle injury.

Zverev said it was poor form for some of the crowd to boo Djokovic off court.

"Novak Djokovic is somebody that has given to the sport for the past 20 years absolutely everything of his life," he said in an on-court interview.

"So please be respectful and really, really show some love for Novak as well."

Djokovic approached the clash with questions over his fitness after needing medical attention in his four-set quarter-final win against Carlos Alcaraz.

But he has demonstrated remarkable powers of recovery more than once in his career and it didn't appear to hinder him initially.

The Serb moved with his customary zip in an opening service game that featured a 27-shot rally and again in saving four break points.

It was then Zverev's turn to save three break points and keep the match on serve at 2-2, with both players blowing hot and cold.

Another break point went begging for the German at 4-4, with Djokovic barely getting 50 percent of his first serves in.

It went to a tight tiebreak where Djokovic netted a simple volley to give Zverev the set and he then approached the German to shake hands.

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