The couple, who met at the 2000 Sydney Olympics, married in April and are expecting their first child this summer.

Before that, Federer could win a maiden French Open title and pull level with Pete Sampras's record of winning 14 Grand Slam crowns.

As Mirka Vavrinec, Federer's wife was a regular player on the women's tour until serious injury pushed her out of the game. In the long term, that's been to his benefit.

"She helped me considerably, as a person. I developed faster, grew faster with her. Thanks to her I was very calm in the important moments in my career. She is always supportive. I owe her a lot," said Federer.

His wife is a regular spectator at matches and will be watching from the sidelines tomorrow when he takes on Gael Monfils for a place in the semi-finals at Roland Garros.

She will also be there should he prevail on Sunday and become only the sixth man in history to win all four Slams.

Many in the game believe the shock defeat of four-time champion Rafael Nadal has cleared the path for the Swiss to finally achieve his lifetime dream.