Djokovic fought through trouble with the shoulder to beat Juan Ignacio Londero 6-4, 7-6 (3), 6-1 on Wednesday.

The defending champion was treated by the trainer multiple times in the match and appeared in trouble when he fell behind 3-0 in the second set. But he battled back to take it in a tiebreaker and had an easy time in the third set.

The No. 1 seed wouldn't reveal much about the nature of the injury in his postmatch interview.

Djokovic is a righty, of course, but he uses his other hand both for ball tosses on serves and on his two-fisted backhand -- and both were less effective for stretches.

"I was definitely tested. This is something I've been carrying for a quite a while now," said Djokovic, who repeatedly shook his left arm between points while serving during his first-round match Monday and did that again this time. "It wasn't easy playing with the pain and you have to fight and hope you get lucky with some shots."

Even though he won for the 35th time in his past 36 Grand Slam matches, including in a fifth-set tiebreaker against Roger Federer at the All England Club on July 14, Djokovic looked uncomfortable and went away for stretches, including trailing 3-0 in the second set.

Asked how he plans to prepare for his next match Friday, Djokovic replied with a laugh: "I'll probably freeze my arm for 48 hours, not do anything with it, and then see what happens."