The No. 2 women's tennis player in the world hopes Serena Williams wins the U.S. Open.

Simona Halep raised some eyebrows last weekend after she lost to the top-ranked American in the Cincinnati final, saying during the trophy presentation, "I know you can do four."

In other words, complete the Grand Slam by winning the U.S. Open. But if Williams takes the title, that means Halep doesn't, and it was unusual to hear a top player even imply such an outcome.

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Halep was still comfortable with that logic when asked about it Saturday, two days before the start of the year's last major tournament.

"If I will not be in the finals, I want her to win," Halep said. "If I will be in the finals with her, I want to win."

Of the U.S. Open title, she added, "Of course I want to win." But she also recognizes that Williams has a very real chance to make history, to become the first player since Steffi Graf in 1988 to complete the Grand Slam.

And unlike other tournaments, Halep's not going to contend the field is wide open. Williams is clearly the favorite, she said.

Perhaps her attitude is simply a reflection of the state of the women's game, where Halep doesn't boast the sort of resume typical of a player ranked that high.

The 23-year-old Romanian has been to just one major final, losing to Maria Sharapova in last year's French Open. Halep acknowledged that in Cincinnati, she didn't come on court with the belief she needed to defeat the 21-time major champion.

At Flushing Meadows, it's understandable that she isn't exactly worrying about the final right now. Her insistence that she plans to take it one match at a time is probably more truth than cliche in this case -- the U.S. Open is the only Grand Slam tournament at which she has never reached the quarters.

The third-seeded Sharapova, meanwhile, was trying to temper expectations Saturday considering she hasn't played since Wimbledon because of a strained right leg muscle. Fourth-seeded Caroline Wozniacki, who lost to Williams in last year's U.S. Open final, has had a bumpy and injury-filled summer of her own.

For the top-ranked men, there are no conflicts in openly rooting for Williams. Players usually evade requests for predictions, but not this time. Novak Djokovic, Roger Federer and Kei Nishikori all came right out and said it: They hope Williams wins.

"I am sending her good vibes," the No. 1-seeded Djokovic said Saturday.

If not for a four-set loss to Stan Wawrinka in the French Open final, Djokovic would be seeking a Grand Slam of his own. That gives him a special appreciation for what Williams has achieved.

"Of course," he said. "I know how tough it is."

Federer, too, is thrilled for the chance to witness history. He and Djokovic have each won three major titles in the same year, but never even the Australian and French opens back-to-back to spark talk of a Grand Slam.

"You don't get this opportunity many times in your career or in tennis, for that matter," Federer said.

With a victory, Williams would also tie Graf for the Open-era record with 22 major titles. Williams said Thursday she appreciated seeing Graf's social media posts cheering on her successes.

After Williams completed her second "Serena Slam" at Wimbledon with her fourth major title in a row, Graf wrote on Facebook: "Just incredible watching Serena continue her winning streak at Wimbledon...truly an amazing accomplishment!!! Congratulations!"

"I really love that, when someone is trying to do the best that they can, that someone as great as Steffi is there to be supportive," Williams said, "and be happy more than anything for the next person."