Wozniacki is Lining up for New York Marathon

The aftermath of a failed relationship: Rory McIlroy walks 18 holes; Caroline Wozniacki runs 26.2 miles.

Wozniacki, the world's 13th-ranked female tennis player, was supposed to marry the golfer Rory McIlroy in November. But McIlroy broke off the engagement in May, days after invitations were sent out. Wozniacki's Plan B: to run the New York City Marathon on November 2.

Wozniacki, a native of Denmark who once spent more than a year atop the women's rankings, will be in the New York field along with Meb Keflezighi, who won the Boston Marathon in April.

Wozniacki said she had contacted New York Road Runners to enter not because of heartbreak, but because competing in the marathon was a personal goal and she wanted to raise money for a charity.

"It's always been on my bucket list," Wozniacki said in an interview Thursday morning. "And always New York City was the one I wanted to do. I've seen it on TV, and I have always thought one day I would do it. November, I looked at my schedule and I didn't really have any plans when my season ended, so I thought, 'Why not do it?'"

If she makes it to the start line, Wozniacki, 24, will be among the few professional athletes from other sports to compete in a marathon during their career. Many athletes from other sports have run marathons, but usually after they retired. Lance Armstrong ran the New York City race in 2007 before staging a comeback to cycling. Jennie Finch, an Olympic softball player, ran in 2011; the speedskater Apolo Ohno in 2011; and the gymnast Kerri Strug in 2008.

Keflezighi, an Olympic silver medalist, won the New York marathon in 2009, the first American to do so since Alberto Salazar in 1982. Keflezighi's victory in Boston ended a 31-year drought for American men.

Wozniacki is expected to compete in the U.S. Open, which begins Aug. 25. The WTA schedule continues into October, though it is uncertain which events she will compete in.

"Obviously, it's going to be hard," she said. "I'm a tennis player first, and that's what my main priority is. At the same time, I'm going to incorporate a lot of longer runs into my training."

While this is her first road race, Wozniacki said she ran 30 to 40 minutes a day as part of her tennis training, either in interval training or in longer runs. Her longest run was 18 kilometers, a little over 11 miles.

Her running playlist: a mix of Rihanna, Calvin Harris, David Guetta, Madonna and Adele. "It gets me into the zone," she said.

One of Wozniacki's running coaches will be on the course with her for the marathon. She said she was not following a specific training plan. About 15 friends will line the course to cheer for her, and she hopes her family will be waiting at the finish line.

"Everyone thinks I'm a little crazy," she said. "But we only live once."

Wozniacki has won 22 titles on the WTA Tour but has never won a Grand Slam event. About a week after McIlroy broke off their engagement, Wozniacki lost in the first round of the French Open. She won the Istanbul Cup, her first WTA title of the year, on July 20 - the same day McIlroy won the British Open.

Wozniacki said she had a target finish time in her head, but she did not want to share it publicly.

"I just need to finish the marathon," she said. "That's my goal, and if I have to crawl over the finish line, I'll do that."