Serena Williams, who will try to win her fifth consecutive Grand Slam title at the U.S. Open, acknowledges that she is facing a difficult draw.

In her quarter of the bracket, the world No. 1 could face fellow Americans Sloane Stephens or CoCo Vandeweghe in the third round, Madison Keys or former No. 2 Agnieszka Radwanska in the fourth round, and either No. 8 seed Karolina Pliskova, Toronto champion Belinda Bencic, or her older sister Venus Williams in the quarterfinals.

“You have Sloane, and I seem to get her every tournament, and Madison is playing very well,” Serena said. “Sloane is playing excellent, so it is nothing simple or easy to go through.”

Serena has only dropped two matches this year, one to Petra Kvitova in Madrid in May, and the other to Bencic two weeks ago in Toronto. The 33-year-old won the Cincinnati tournament last week.

"I don’t put pressure on myself to do anything here this year because I’m obviously going to be excited to compete here next year," she said. "I always dreamed of winning the [calendar-year] Grand Slam. But it was just a dream. I never thought I would be close to doing something like that."