Novak Djokovic will look to keep recent shoulder injury at bay as he resumes his U.S. Open title defence in the third round, while Serena Williams will look to take another step closer to a record-tying 24th Grand Slam title on Friday.

Djokovic will conclude the evening session inside Arthur Ashe Stadium when he faces American Denis Kudla in a rematch of their second-round Wimbledon meeting, which the Serbian won in straight sets.

But top-seeded Djokovic, who has won four of the last five Grand Slams, may need his left shoulder to cooperate as sudden pain in his second-round match affected his serve and backhand and nearly ended his title defense.

"Good thing about Grand Slams is you have a day off in between the matches," said Djokovic. "I'm hoping that with proper medical help and treatments, I'll be able to get myself in a better state."

Roger Federer will try to avoid another slow start when he kicks off the day session on Arthur Ashe against Briton Dan Evans and will be followed on the court by six-times champion Williams.

Federer has lost the opening set in each of his first two matches before flipping a switch and cruising to the finish line in dominant fashion.

The 20-times Grand Slam champion, who improved to 2-0 all-time against Evans when he beat him in the second round of the Australian Open this year, is not losing any sleep over his sluggish starts.

"I don't think there is per se a secret to a good start other than warming up well, being well-prepared mentally. Not underestimating your opponent ... You know me, I will always do that," said Federer.

"So when it happens like this back-to-back matches, you know, it's just a bit frustrating more than anything ... but, yeah, can only do better, which is a great thing moving forward."

Williams will also be keen to avoid falling into an early hole after being dealt a scare when she dropped the first set in her second-round match against American Caty McNally.

The 37-year-old will cap the afternoon session on the main showcourt when she battles Wimbledon quarter-finalist Karolina Muchova for the first time in her career.

"Muchova did well in Wimbledon. Actually got to see some of her matches, but not enough," Williams said when asked about the test that awaits her in the third-round.