Djokovic struggled as the first set went on, grimacing in pain and pulling up on his leg. He received treatment after Alcaraz broke to lead 5-4 and, when he returned, quickly lost the opening set.

His physical problems persisted in the second set and the No. 7 seed continued to wince in pain. But he kicked into life at the perfect time, breaking at the end to snatch the set and level the score.

Djokovic continued to raise his level and there were no longer any signs of injury - apart from when he took two more painkillers during the fourth set. Afterwards, the 10-time champion addressed his physical concerns and confessed that he almost quit the match.

"Well since I’m still in the tournament, I don’t want to reveal too much obviously," Djokovic started. "But yeah, the medication started to kick in and that helped, no doubt. I had to take another dose. This sounds awful! Me taking another dose. But I had to.

"I didn’t know, to be honest, if I lost the second set I didn’t know if I would continue playing. But I felt better and better, managed to play a great couple of games to end the second set."

Djokovic was also encouraged when he saw Alcaraz's level begin to drop. By the end of the match, he felt fine.

He continued: "And then I saw that Carlos was hesitant a little bit from the back of the court and I took my chances and started to feel better, started to move better. So it didn’t bother me, it didn’t create any hindrance towards the end of the match, only in that second set."

However, the world No. 7 may not be in the clear just yet. "Obviously when the medication starts to release, I’ll see what the reality is tomorrow morning. But right now I’ll just try to be in the moment and enjoy this victory," he said, hinting that Friday's semi-final was up in the air.

Djokovic has the luxury of an extra day off before his next match against Alexander Zverev. The men's semi-finals will be played on Friday and the 37-year-old admitted he needed all the rest he could get.

Doubling-down on his concerns about being ready for the match, he continued: "I guess the key is recovery for me now. To be honest, that’s all I’m thinking about.

"The extra day with no match comes at the perfect time for me. Let’s see if it’s going to be good enough on Friday. Hopefully I can come out because Sascha is playing some of the best tennis he’s played."

Djokovic famously played through a hamstring injury when he last lifted the title in Melbourne in 2023 and he used that experience to help him against Alcaraz. He's now hoping to do the same when he meets world No. 2 Zverev.

"In that perspective, the way you’re explaining, I think comparing to the 2023 performances I had, it does help mentally," he explained.

"Because you just, all of a sudden, start to play a bit more aggressive, you go through your shots more so I guess that’s going to be necessary for me in a couple of days time when I face Zverev."