Lilian Thuram, France's most capped player, said yesterday that he will be unable to sign for Paris Saint-Germain after having a heart condition diagnosed.

The 36-year-old World Cup winner had been scheduled to sign an initial one-year contract with the French club, but he said that a “heart defect” had been detected during a medical visit to Paris. “If I'm holding this press conference it's unfortunately not to announce my signing with PSG but to tell you that doctors have detected a heart defect,” he said. “It seems that it's the same illness that my brother had a few years ago and from which he died on a basketball court.”

Thuram explained that doctors will continue their tests and they should have the final results in a month. He added that he would await the final results before deciding if he would end his footballing career.

Charles Villeneuve, the PSG president, said that the club would decide after the results whether to sign Thuram.

“Like all top athletes he has a large heart, but the figures are close to the danger limits,” Eric Rolland, the PSG medical director, said. “For most people, a slightly enlarged heart doesn't interrupt their normal life, but with severe enlargement, exercise must be limited to control stress on the heart.”

Thuram has spent the past two seasons at Barcelona but has struggled to hold down a first-team place. The former Juventus defender had a poor Euro 2008 and was left out of France's final group match against Italy, who won 2-0 to knock their rivals out of the tournament.