There is not a lot we know about Sebastien Grosjean. First up is that we don't really know how he got here because we haven't been looking writes Johnny Watterson at Wimbledon

One of the conceits we have in writing about Wimbledon is to ignore those players that in our ignorance we believe cannot win then hardly notice when they are filtered out of the draw on an outside court. Grosjean is such a player. French and from a resolutely clay-court background, he has been studiously ignored, despite reaching the semi-final here last year.

We know he likes shoes, has 60 pairs, has a beautiful daughter, Lola, and son, Tom, is a fan of Olympic Marseille and today faces Roger Federer for a place in the Wimbledon final. Grosjean is the player who can walk through the rat-runs linking these courts and 30,000 people without turning a head. He looks vaguely familiar: that French guy with the baseball hat turned around.

Florida-based, the 26-year-old hasn't played Federer in three years, which, in terms of the Swiss number one's career graph, was back in the Cretaceous period. Three times in 2001 they met, the Frenchman winning all against the then teenager. Federer is no longer callow.

Grosjean will meet the player who can meet fire with ice or ice with fire. He is adaptable, taking on Hewitt two days ago and beating him from the back of the court, Hewitt's patch. Federer has also won from the net, mid-court, volleying from the base line, bending balls out of court and back in to hit the corners. With no physical frailties, perhaps the only weakness is in his head at times. Federer's perceived invincibility might be Grosjean's inspiration. He has little to lose and, unlike his opponent, can take comfort from the fact he has reached this point in the tournament without dropping a set.

"For sure he (Federer) is the best player on the tour," said Grosjean. "Especially on grass. He didn't lose a match since last year (on grass). Now the semis - anything can happen. I have to try to play aggressive and to enjoy the match."

Federer is contesting his third Grand Slam semi-final. On the previous two, last year here and this year in Australia, he has gone on to win the title.

Inescapably the favourite, Federer is, by the seeding committee's judgement, scheduled to meet second seed Andy Roddick in Sunday's final.

Roddick's opponent in the other semi-final is another player with little to lose, this time a darker horse but one who has discovered a blinding vein of form. Mario Ancic killed the British dream and now hopes to supplant the American on Centre Court on Independence Day. The two met at Queens prior to Wimbledon, where Roddick narrowly won in three sets.

"I was lucky to win, to be honest," said Roddick. "I knew he could play. He's serving great. I mean I don't know what's in the water in Croatia but it seems like every player is over seven feet tall. He's kind of saying 'this is what I got, deal with it'. And I think that's a good mindset for him to have."

Roddick's evolution has shown a discernible change. Quicker around court and more patient in the points, he no longer wants to ice his rival on every shot but picks his moment. He also has a phenomenal first and second serve.

"For a guy who hits his second serve that hard, he doesn't hit a lot of double faults," observed Hewitt on Wednesday. Ancic? He has the Ivanisevic gene. Like Grosjean he has sneaked up in the long grass, meaning form. That alone should cause some anxiety in the Roddick camp.