The Portuguese was comfortably beaten by the 13-time Grand Slam champion on Monday, although the Serb struggled in the heat.
In between the second and third sets of his 6-3 6-4 6-3 win over Sousa, Djokovic left the court and didnt return for about six-and-a-half minutes.
The world No. 68 complained to British umpire James Keothavong over the amount of time the Wimbledon champion was taking to come back and discussed the issue during his post-match press conference.
And while he didnt think Djokovic was trying to seek an advantage, he expressed his frustration at the lack of time limit imposed on such breaks away from the court.
Well, Im not happy about that, but thats a rule, he said. He can have a toilet break.
I was asking him why hes taking so long. There is no limit for a break, toilet break. So I think its a rule that its a little bit messy.
But I was not complaining. I was just asking, How much time he was taking? For me it was too much between the second and third set. But, yeah, the rule says you can have a toilet break, so he got it.
Its just a rule. I can use it, as well. I dont think that he used it to get an advantage of the match.
Djokovic also took a medical timeout in the third set as he struggled in the New York heat and Sousa admitted there was no notable difference in the Serbs level of performance between the two sets after the break.
I was more focused on me than on him, he added. But, yeah, I dont know. I
didnt see any difference between the second and third set. He was playing good.
Yeah, he called the physio at 2-1 of the third set. So, yeah, I mean, nothing to say about that.