Serena's toughness in question

WIMBLEDON, England -- It may be the most anticipated women's match of the season. The not-quite-past of women's tennis and the possible future will clash when Serena Williams meets Petra Kvitova on Centre Court in the Wimbledon quarterfinals, and the result will tell us a little more about the present.

For more than a year now, the women's game has seemed struck in transition between the old and the new. The veterans and up-and-comers have traded Grand Slams back and forth. The past four majors have gone to Kvitova, Samantha Stosur, Victoria Azarenka and Maria Sharapova. Whoever wins this quarterfinal meeting will emerge as the tournament favorite from here onward, so the result could well determine which way the generational pendulum swings next.

Much has changed for Williams, 30, and Kvitova, 22, since they last met here at Wimbledon two years ago. Williams won that semifinal meeting and went on to take the title, but then came a well-documented string of medical problems that started when she cut her feet during an evening out in Munich the following week. She returned almost a year later, but despite strong play that has netted her four WTA titles, she has yet to triumph at a major since. A first-round loss to Virginie Razzano at the French Open from a set and 5-1 up in the tiebreaker raised significant questions about Williams' current mental toughness -- perhaps a first in her career.

Williams dismissed the concern, saying, "I'm Serena Williams. I'm very confident."

But after winning her first two Wimbledon matches easily, Williams has struggled in the past couple of rounds and admits that the Razzano match lingers. "I think it has spillover effect, and I need to get over that. I was really upset, and I've just got to move on. So that's what I'm working on," she said. "Whether or not I'm past it or not, I have to force myself to get past it."

She is looking forward to finding better form, having just barely edged through against Yaroslava Shvedova in the fourth round.

"I just felt like today I was sluggish out there, just pulling myself together mentally," Serena said after winning 7-5 in the third set. "But like I said, I feel like I can do a lot better, which is very comforting, because if this is my best I'm in trouble.

"As the tournament goes on and on, I tend to relax more and more and realize that this is a great opportunity for me."

Kvitova is also trying to relax her way through the tournament, admitting that her nervous first-round start "was a disaster" but that things have been easier since. She had to come from a set and a break down against Francesca Schiavone in her previous match but handled the rain and disruption better than the Italian veteran.

Now comes the toughest test yet. In last year's final against Sharapova, Kvitova blasted her way through and seemed to feel no pressure on her way to her first Grand Slam title -- much like Sharapova seven years earlier -- but she is now much more aware of the stakes.

"I think it will be huge match for both of us, and I'm looking forward to play against her. Looking forward to have a challenge," Kvitova said.

Williams said she has trouble recalling her semifinal against Kvitova two years ago but knows what a threat the Czech is these days. "I know she served well. Then she went on to win the title the next year, so she's obviously a great grass-court player, as well as I am. I'll be ready," Williams said.

In the rest of the quarterfinals, youth has largely won out over experience. The oldest player apart from Williams is Maria Kirilenko, a veteran at 25 and going up against Agnieszka Radwanska, 23, but a relative newcomer to the upset ranks. With neither a power player, it will be a match of quiet guile and skill.

The other match in the top half features rising Germans Sabine Lisicki and Angelique Kerber. The 22-year-old Lisicki reached the semifinals as a wild card last year, while the 24-year-old Kerber leads the tour in matches won this season, and the two are expected to have a close battle after knocking out the two favorites in their section. Lisicki defeated Sharapova, while Kerber steamrolled Kim Clijsters in her Wimbledon farewell.

Whatever the results, there will be a new Grand Slam finalist at Wimbledon this year since none of the four in the top half has ever made it that far.

The other quarterfinal in the bottom is a rerun of last year's matchup, pitting Australian Open champ Azarenka against the youngest player in the draw, 21-year-old Tamira Paszek. Paszek, however, got her start on the pro circuit at 14 and has been through plenty of highs and lows in her career. She'll take a nine-match win streak on grass into the match against Azarenka, who began the year with a 26-match win streak and is looking in good form after a difficult few months.

But center stage will belong to Williams and Kvitova, the only two former champions left, and one will emerge as this year's most likely champion to come.