The Serb crashed out in the semi-finals at Flushing Meadows courtesy of a 6-4 1-6 7-6 6-3 defeat which preventing him from reaching a fifth consecutive US Open final.
The top seed acknowledged that he was beaten by the "better" player on the day and is hoping to bounce back quickly and end the year on a high.
"Other than that second set, my game today was not even close to what I wanted it to be. A lot of unforced errors, a lot of short balls. I just wasn't myself," Djokovic told reporters.
"I felt like I could have gone at least a step further here, but it was disappointing today. It's sport. I have to congratulate the better opponent and move on and try to finish off this year hopefully as close as I can to last year."
Djokovic has had issues with hot conditions before in his career, but he refused to use the temperature as an excuse for his performance this evening.
"It was the same for both players. It was not easy to play in these conditions, but also he had more hours spent on the court. So it's no excuse," he added.