FORMER FIFA PRESIDENT Sepp Blatter told the opening day of his criminal trial that he was troubled by chest pains and unable to testify.

Once the most powerful man in the world of football, Blatter is facing charges of defrauding Fifa in a Swiss criminal court.

He is on trial along with former France football great Michel Platini, his former protege who had been considered Blatter’s successor as president of the governing body of the sport.

Platini was also in court, sitting with an interpreter behind Blatter.

The 86-year-old Blatter was due to be questioned on Wednesday but when he was called to the stand about an hour before the court was scheduled to adjourn — following several motions from the defence that were all rejected — he asked instead to respond on Thursday morning, when Platini is also set to be questioned.

“I’m not well. I have these problems that come and go,” Blatter, sitting with his lawyer on a long bench, said in a voice barely louder than a whisper.

“I can’t breathe well. I don’t feel capable at the moment of responding to an interrogation.”

Blatter had earlier left the court for a break — another concession given to him because of his age — walking slowly out and clutching onto the shoulder of his daughter, Corinne Blatter Andenmatten.

“I hope that I’ll feel better tomorrow,” Blatter said.

The trial is expected to last 11 days and the court will sit only until lunchtime each day because of Blatter’s health. He was in a coma following heart surgery 18 months ago.

The former Fifa president arrived at the Federal Criminal Court of Switzerland in Bellinzona in a buoyant mood, expressing confidence when asked about his chances.

“Absolutely, absolutely, absolutely,” Blatter said. “I feel optimistic, like always. With the beautiful sunshine. It’s the first day of a trial that’s going to last almost two weeks. If I didn’t feel confident the first day that would be bad. I am very confident.”

Blatter’s 17-year reign as Fifa president came to an end in June 2015, when he resigned amid a corruption scandal. A few months later, federal prosecutors in Switzerland revealed their investigation into a two million US dollars payment from Fifa to Platini from four years earlier.

Michel Platini leaving the Swiss Federal Criminal Court in Bellinzona, Switzerland. AP / PA Images AP / PA Images / PA Images

Both Blatter and Platini have long denied wrongdoing and claim they had a verbal deal in 1998 for the money. That defence first failed with judges at the Fifa ethics committee, which banned them from football, and later in separate appeals at the Court of Arbitration for Sport.

“Is soccer by my side? Soccer is me. It’s been 45 years that I’ve been serving Fifa, international soccer. And it’s my life, it’s my professional life,” Blatter added before going inside.

“I now have to defend myself a bit, but I will defend myself well, with a lawyer and that’s it, because I have a clean conscience.”

The fallout from the case also ended Platini’s campaign to succeed his former mentor and saw him removed as president of Uefa, the governing body of European soccer.

Platini’s lawyer, Dominic Nellen, tried to get the trial moved to a local court but his request was rejected.

“Finally, the hearing has started but in the wrong stadium,” Mr Nellen told the court.

The lawyers for Blatter and Platini also failed to dismiss Fifa’s civil claim to recoup the money.

“The payment of two million from Blatter to Platini was never approved by Fifa,” the governing body’s lawyer, Catherine Hohl-Chirazi, said.

“It’s clear that the federation was also damaged: two million was stolen.”

Both Blatter and Platini are expected to give closing statements on 22 June, when the trial ends.

The three federal judges hearing the case are scheduled to deliver their verdict on 8 July. Blatter and Platini each face up to five years in prison, but suspended sentences are a likely option.