Thirty-year-old Williams marked a two-year return from injury by winning Wimbledon and Olympic gold earlier this summer - all of which has made her the favourite to win the ongoing US Open at Flushing Meadows.
With that in mind, Djokovic has expressed his relief that Williams will be competing in the women's draw.
"It's incredible. Nobody knows where she is going to stop and she keeps on going and dominating," said Djokovic. "I'm happy I'm in men's tennis and not needing to face her."
Djokovic and Williams are both due to open up their US Open campaigns tomorrow.