The Serbian tennis star overcame Enzo Couacaud in four sets to reach round three in Melbourne but is feeling the discomfort with his hamstring problem.
Djokovic told Eurosport: "It’s not good at all to be honest.
"I’ll take it day-to-day, it was better [in the] last match, the feeling, than tonight.
"That’s all I can say. It’s up to God, and my physio to help me. Let’s take it day by day, I hope I’ll be able to recover."
Djokovic was annoyed during the match by a fan he called "drunk out of his mind" and he was grateful to progress after a challenging test.
The nine-time Australian Open winner said: "I’m just glad to get through this kind of match and in four sets.
"Obviously I wanted to get through in three but credit to him for playing some really good tennis towards the end of the second.
"Some really interesting circumstances you have to deal with, but I guess that’s Grand Slam. It can be electric in both a positive and negative way. For a player on the court, you just have to accept it and get the most out of it."
Several players have criticised the balls at this year's event and Djokovic admits that they make it difficult to produce winners during matches.
He said: "The balls are a bit slower this year than they were a few years ago when I played last. I think quite a few players complained about it.
"I don’t complain, I’m just noting and commenting that the balls are a bit slower which of course, in these conditions makes it difficult to penetrate through the court and try and make winners and especially against someone like Enzo who is a very good athlete."