Paris - Roger Federer launched a battle for the heart and soul of the French Open on Monday following controversial plans that could see the historic Roland Garros site, in plush, western Paris, abandoned.
If an extension plan at the current site is not backed, then there are three alternative areas being examined - Marne-la-Vallee, which is near Euro Disney, Versailles and Gonesse.
Paris city council, on the other hand, has unveiled an extension project for the current site that would involve installing a retractable roof on Centre Court and the use of a hectare of the adjacent Boulogne forest.
But Federer has urged caution.
"The people, the media, ask more. We want to have more, and it's not easy for the tournament, but we have to do our best, and do the best for the tournament," said the world number one and defending champion.
"So if we move elsewhere, does it make sense? What about the soul of Roland Garros? This is what we might miss after. So let's think twice before we act."
If the French Open stays in Paris, the cost of extending the site is estimated to be 200 million euros, while relocation would cost 600 million euros.
A final decision will be made in February 2011.
Four-time champion Justine Henin, who is playing at Roland Garros after a three-year absence, said she would support the French tennis federation's decision but admitted her preference was for the tournament to stay put.
"It's difficult to imagine that Roland Garros will be elsewhere," she said.
"I hope they will find solutions to keep the tournament here, because the history is behind this place.
"But sometimes, some decisions are necessary and logical. So let's stay down to earth about this and let's take the best decision."