'I'll keep going': Djokovic vows to fight on

'I'll keep going. You know, 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'

Novak Djokovic pledged to continue his hunt for a record 25th Grand Slam title as he processed the disappointment of retiring from Friday's Australian Open semi-final due to a muscle injury.

Djokovic retired injured after losing the first set 7-6(5) to Alexander Zverev and the 10-times champion made a pained exit from Rod Laver Arena amid booing from sections of the crowd.

It was his second injury setback at the Grand Slams in a year, having pulled out of the French Open with a knee problem before his quarter-final against Casper Ruud.

Four months before his 38th birthday, time may be catching up on the Serbian great but he remained adamant he had more to give in the twilight of an extraordinary career.

"It's not like I'm worrying 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," he told reporters.

"So it is true that (I am) getting injured quite a bit the last few years."

"I don't know what exactly is the reason for that. Maybe several different factors."

"But I'll keep going. You know, 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 came into the match under a cloud after a draining but brilliant quarter-final win over Carlos Alcaraz in which he took a lengthy medical timeout after the first set.

He had his left thigh taped when he took the court against Zverev but there were few signs of the strain until quite late in the set.

Having battled through a hamstring injury during his title run two years ago, and an abdominal muscle tear during his 2021 championship at Melbourne Park, Djokovic's retirement stunned the crowd and also surprised Zverev.

The Serb said he might have continued to battle on if he had won the set but questioned whether it would have been worth it.

Though "upset and disappointed", Djokovic was ultimately philosophical, saying he would cheer for Zverev as the German bids for his first Grand Slam title after defeats in two finals.

"I actually thought I played really well, as well as I played the last 12 months, to be honest," Djokovic said.

"I liked my chances today ... A lot of positives to take in terms of how I played semi-finals."

"It's a very good results considering the circumstances. But it's not satisfying to me, you know, for my standards."

"I always look for the highest goal, to reach the finals and fight for a trophy."

On his new partnership with Andy Murray, who helped the Serb prepare for the year's first Grand Slam, Djokovic was not sure if they would continue together.

"I'll definitely have a chat with Andy and thank him for being here with me. You know, give him my feedback, which is, of course, positive, and see how he feels," said Djokovic.

"We are still hotheaded and disappointed, so it's kind of hard to switch the page and start talking about what the next steps are."