Federer's secret weapon

Miroslava Vavrinec's Olympic career was brief and far from glorious. Her only appearance, at the Sydney Games nine years ago, ended in a first-round exit at the hands of Elena Dementieva. She also fell at the first hurdle in the doubles, partnering Emmanuelle Gagliardi to defeat against the Venezuelans Milagros Sequera and Maria Vento.

The Games, nevertheless, were not without consequence for the 22-year-old. It was in Sydney that a fellow Swiss tennis player started paying her close attention. "I couldn't work out why he wanted to talk to me so much," she said later. "Then, near the end of the Games, he kissed me."

Roger Federer, who was 19, had said previously that he would "choose tennis over a girlfriend". However, since those first days of his relationship with Mirka (now known everywhere by the shortened version of her name), Federer has proved tennis and love can be a perfect match.

Speak to any of the five-times Wimbledon champion's close associates and they will tell you that he could not have achieved his success without the support of the woman who became his wife this year and will soon give birth to their first child. For the last six years Mirka has been his constant companion and the key player in Team Federer.

Having started by helping with his media relations and organising his travel, she has played an increasingly important role in all aspects of his professional life. She has even been his hitting partner.

"She has been with me day in and day out, throughout the world, and has helped me considerably as a person," Federer said recently. "I developed faster, grew faster with her. Thanks to her I have been very calm in the important moments in my career. She has always been here, always supportive. I owe her a lot."

It is no surprise many tennis players end up playing more than mixed doubles with each other. Globe-trotting is hardly an ideal platform for a steady relationship, unless your partner follows the same lifestyle. Even then it is not easy. Ana Ivanovic and Fernando Verdasco dated at the end of last year but their relationship did not last long in the public spotlight.

Nevertheless, there have been plenty of tennis marriages that have worked. Lew Hoad, like Federer the Adonis of his day, married his wife, Jenny, in Wimbledon in 1955 and they were together until his death 39 years later. John Newcombe married his wife, Angie, a German tennis player, in 1966. In more recent times Andre Agassi wed Steffi Graf.

Things might have been different for Roger and Mirka had her career taken off, but at 24 she played her last tournament because of a foot injury. It was a short career, for she had not taken up tennis until the age of nine.

Like Martina Hingis, Mirka was born in the Slovakian part of Czechoslovakia. Her family left for Switzerland when she was two. When she was nine they met another exile from Czechoslovakia, Martina Navratilova, who was playing in a tournament in Germany. Navratilova, impressed by Mirka's athletic frame, suggested she should try tennis. Mirka quickly took to the sport and was Swiss junior champion at 15. She had already taken up Swiss citizenship when she met Federer for the first time in 1997. She broke into the world's top 100 three years later.

The high point of her career came when she made the third round of the 2001 US Open, losing to Justine Henin, and reached her career-high world ranking of 76. The following January she partnered Federer in the Hopman Cup team event, but three months later her career was over.

By the following year, Mirka was attending tournaments with Federer and helping with his media dealings. Fiercely protective of her man, she has been known to burst into interviews, tapping her watch if she believes they have been going on too long. Nevertheless, nearly all who deal with her, whether journalists, officials or anyone else from the tennis world, like her business-like approach.

At Wimbledon in 2003, Mirka joined Federer in a cramped flat at Wimbledon. It proved a winning formula as Federer won his first Grand Slam title. At the end of the year Federer moved out of his parents' home and moved with Mirka into an apartment in Oberwil, near Basel. The partnership has blossomed in all respects ever since. Even the domestic chores are shared. "We make sure that we divide the work evenly," Federer once said.

In the early stages they did not want to be photographed together, though their attitude relaxed as Mirka became a permanent fixture in Federer's entourage. Nevertheless, they fiercely protect their privacy. Only close family and friends are ever invited into their home. Mirka nearly always attends Federer's matches but shuns the limelight and no longer gives interviews.

Team Federer is small and tight-knit. In Doha this year Mirka, now 31, was his only travelling companion. Generally the team numbers at least four. Severin Luthi, the Swiss Davis Cup captain, is his principal tennis associate, and Pierre Paganini his fitness adviser. Tony Godsick is his agent and former player Geraldine Dondit has taken over media duties during Mirka's pregnancy. Reto Staubli, a former player, is one of Federer's closest friends and sometimes his hitting partner. Federer's parents complete the line-up. Of the current generation of players, the closest to Federer are his Davis Cup colleagues, Yves Allegro, who is a former flat-mate, Marco Chiudinelli and Stanislas Wawrinka.

The tightness of the team was shown when nobody leaked news of Federer's Easter wedding, attended only by his inner circle. "It was nice sharing the moment with my family and closest friends," Federer said at the time. "I got very emotional – yet again. It was very nice. It was just nice to know that she loves me so much and I love her so much."

He added: "It's nice to be calling Mirka my wife and not my girlfriend. That's just a big change for me and maybe takes a bit of getting used to."

Will having a baby – whose due date is another secret – change their lives? The intention is for the family to travel together as much as possible. "It's obviously going to have a very positive impact for my personal life," Federer said. "I think for my tennis life, too, it's just going to make it more exciting, trying to find the best ways to balance both things. I know I'll be as professional as ever, even when the baby is there."

Other players who have become fathers warn life can become complicated. Ivan Ljubicic, who has a seven-month-old son, said: "I'm sure it's going to be a shock for him. Your life changes completely. Priorities are different. You're not the one in the family who's the most important. You kind of lose your wife for a while."

Federer insists, however, that having a baby can have only a positive effect. "I always had the dream that once I became No 1 in the world that if I had a child I hoped I would have it early enough so the child can see me playing," he said.

Ace dads: The father effect

Roger Federer might be hoping that Mirka does not follow the example of Rod Laver's wife, Mary, who gave birth to their son, Rick, in California within hours of Laver (below) winning the US Open in New York in 1969. The result completed his second Grand Slam, but it was the last of his major wins. Since 1980 only eight men have won Grand Slam tournaments after becoming fathers. Pat Cash, Andres Gomez, Petr Korda and Albert Costa all won only one major, while Boris Becker, Yevgeny Kafelnikov and Andre Agassi added only one to their previous tallies as fathers. Other multiple champions like John McEnroe, Ivan Lendl and Stefan Edberg all failed to win more Grand Slam crowns after becoming fathers. The big exception to the rule was Jimmy Connors, who won three of his eight Grand Slam titles after the birth of his son.