Melanie Oudin hasn't won a main-draw tennis match since the U.S. Open, when she captivated the crowd with her relentless fight, fist pumps and an unwillingness to lose easily.

Down a set to Maria Sharapova? Nothing a few all-out, attacking-the-corners forehands couldn't make right.

Oudin, 18, made it to the quarterfinals in New York, an unseeded player who upset the fourth-, 13th- and 29th-seeded players along the way. She was mad after losing to eventual runner-up Caroline Wozniacki.

Then Oudin left, just as Sports Illustrated was revealing that her father, John, had filed for divorce from her mother, Leslie, in July 2008 and cited a relationship between Oudin's coach, Brian de Villiers, and her mother.

Since the Open, the 49th-ranked Oudin has lost in the qualifiers for events in Tokyo and Beijing and fought off a flu bug. Now she is in Italy as the top-ranked player for the U.S. in the finals of the Federation Cup.

Oudin, in a telephone interview Wednesday from Italy, called her time since the U.S. Open "crazy."

"It's been a big change in my life," she said, referring both to her breakthrough tennis and the sudden publicity given to an emotional family situation.

"All of what happened in New York was a huge surprise for everyone, for my friends, for my family," she said. "My life has changed for good and I'm learning how to deal with everything, how to handle situations I never thought about. I feel a lot better about stuff now. It's out there and I'll just be honest about stuff."

The U.S. will try for its first Fed Cup title since 2000 against Italy on Saturday and Sunday in Reggio Calabria on a court of slow red clay and against a team that features two top-20 players -- No. 11 Flavia Pennetta (who won the L.A. Open last summer) and No. 16 Francesca Schiavone.

Until last week, Fed Cup captain Mary Joe Fernandez thought she'd be leading a team with top-ranked Serena Williams and sixth-ranked Venus Williams along with Oudin and the world's No. 1-rated doubles player Liezel Huber.

But first Venus and then, more unexpectedly, Serena withdrew from the team.

Both sisters cited fatigue after a long season. Serena, however, has been sending Twitter messages about her time spent this week in London, including making an appearance on a television comedy show with Jonathan Ross.

"I was very disappointed," Fernandez said Wednesday from Italy. "And I was very surprised. I wanted to bring our best team and I had been told nothing since the Open except that Serena and Venus really wanted to play. They really showed a lot of interest.

"It's too bad because they would have brought a lot of attention to this event. And it would have given our young ones two great veterans to look up to and learn from."

Fernandez also noted that had Serena helped the U.S. team to a Fed Cup championship, Williams might have helped repolish an image tarnished by her obscene outburst against a lineswoman at the U.S. Open.

"I think she could have helped herself with that, yes," Fernandez said.

Oudin, who is in Italy without her mother or her coach, is one of those young ones Fernandez is talking about.

The Georgia teenager is expected to play two singles matches in the best-of-five event, and either 20-year-old Alexa Glatch from Newport Beach or 20-year-old Vania King from Long Beach will play the other two. One of them will join Huber in the doubles Sunday. Fernandez doesn't have to give her lineup until an hour before play begins Saturday.

But Oudin will be ready, noting that life outside the U.S. has been easier.

"Nobody here in Italy knows who I am," she said. "And they sure won't be cheering for me so it will be very different from New York. And that will be fine."

diane.pucin@latimes.com