He revealed he will be fined for the Doha incident, but didn't disclose how much.
"I definitely didn't want to hit the ball at anybody, just happened," he said. "Fortunate not to get a bigger fine.
"On the other hand, unfortunate to actually have that incident happen. I have to be more careful, I guess, in the future."
Djokovic said he did not see the ball hit the spectator, but would "pay my consequences for that".
"I accept that I made a mistake," he said. "It was not intentional at all.
"Of course, people get hit, especially in the first rows, from big serves and so forth.
"It happens, it's not the first time. This is something that definitely cannot happen, I mean, from my side.
"I accept the consequence, absolutely."