Serena Williams
Serena Williams (L) and Venus Williams are facing each other for the 16th time in a Grand Slam tournament. In this picture, Serena and Venus Williams of United States pose before the start of their tennis match during Day 8 of BNP Paribas Open in Indian Wells, California, March 12, 2018. Kevork Djansezian/Getty Images

Serena Williams will face her sister Venus in the third round of the US Open on Friday and admitted it will be a really tough match very early in the tournament.

The two sisters, who are seeded 16 and 17 in the tournament are meeting much earlier than expected due to their low rankings. It is the first time they are meeting at this stage of a Grand Slam since the 1998 Australian Open.

Serena was the world number one before she took more than a year off from the game to give birth to daughter Alexis Olympia Ohanian. She returned earlier this year and reached the final of Wimbledon in what was just her fourth tournament of the season.

The 36-year-old is seeking a record breaking 24th women’s singles Grand Slam title at Flushing Meadows but accepts that it will be a very tough match against an opponent she has faced 29 times in the past. Serena and Venus have already played against each other once this year when the former lost to her older sister at the BNP Paribas Open.

The six-time US Open winner admitted it was tough coming up against her sister, as it was difficult to beat a person when you always root for them to win. She believes Venus faces the same difficulty.

Serena and Venus have faced each other 15 times in Grand Slams thus far and just three of them have gone the distance with 12 finishing in straight sets. Serena has an edge over her sister, but in the recent past Venus has won their last two encounters.

Serena remains confident both the players will play their best when they come face-to-face on Friday — like they have done all their careers when pitted against each other.

“I wouldn't say it's exciting. But it's definitely going to be a really tough match for me. Once again, it's early in the tournament. You know, it is what it is,” Serena said after her win against Germany’s Carina Witthoeft in the second round, as quoted on Tennis World USA. “I never root against her, no matter what. So I think that's the toughest part for me. When you always want someone to win, to have to beat them. I know the same thing is for her. When she beats me, she always roots for me as well. I think that's just the hardest part.

“The best part is we bring out the best in each other. I know when I play her, I have to play some of my best tennis. She does, too,” the American added. “It propels us to continue to play that for the tournament. It sets a tone for us. I feel like throughout our career, we have pushed each other to be the best that we can be, and be Venus and Serena Williams.”