Michel Platini, the suspended Uefa chief, arrived Friday at the Court of Arbitration for Sport in the Swiss city of Lausanne to appeal his six-year
Fifa ban for ethics violations, with his future in football hanging in the outcome.
"Today the match begins, a new match, the final, and we are all on the same page. I'm optimistic, we're going to win," Platini told reporters.
The stakes could not be higher for the 60-year-old former Juventus star and suspended head of Uefa, the European football confederation.
A favourable verdict and he will take his place in the stands at the Stade de France for the Euro 2016 opener between hosts France and Romania on June 10.
A negative verdict will mean he will be barred from entering the national stadium, his glittering career in the sport having come to an ignominious end.
The Frenchman has been sanctioned over an infamous two million Swiss franc ($2 million, 1.8 million euro) payment he received in 2011 from then-Fifa president Sepp Blatter.
Fifa's ethics committee in December banned both men from all football activities for eight years. The suspensions were cut to six years in February.
Both men insist they did nothing wrong and that the payment was part of a legitimate oral contract tied to consulting work that Platini did for Fifa between 1999 and 2002.
The affair has already cost him a shot at becoming head of world football as he was forced to pull out of the race to become Fifa president in an election won by his No 2 at Uefa, Gianni Infantino.
Uefa has said it will not replace Platini until all his appeals are exhausted, so if the former French star is successful at CAS he could reclaim his job in time to preside over Euro 2016.
Platini's entourage is hoping for a decision "before May 3" when Uefa holds its congress in Budapest.
Blatter, who is due to testify Friday, has also appealed to CAS and is awaiting a date for his hearing.