The head of the lawyer's practice defending Michel Platini is confident that his client will be cleared in time to be reinstated as UEFA president before Euro 2016.
In February, Platini and former FIFA president Sepp Blatter both had their bans from football reduced from eight to six years by a FIFA appeals committee.
The punishment had initially been imposed by the world governing body's ethics committee over a conflict of interest in a two million Swiss franc (£1.35m) payment made to Platini by FIFA in 2011.
The payment was made to the Frenchman nine years after he stopped working as an advisor to then FIFA president Blatter and it was also investigated by Swiss authorities. Both men admit that it was not covered by a written contract but deny any wrongdoing.
Platini is challenging his suspension at the Court of Arbitration for Sport (CAS) and Yves Wehrli told L'Equipe that he expects Friday's hearing to result in a decision that would "completely clear" his client.
"It's the first time that we're going in front of an independent jurisdiction made up of eminent legal experts," Wehrli said.
"Until now, we were confronted by the internal systems of FIFA... we're therefore expecting a decision that confirms his good faith and that he's innocent of the accusations brought against him."
Former France international Platini's suspension ended his chances of becoming FIFA president and instead Gianni Infantino, his former right-hand man at UEFA, was elected to the role in February.
But Wehrli is hopeful that the former Juventus midfielder will be exonerated in time to oversee Euro 2016, which is taking place in his homeland this summer.
"Let's be clear: if Michel Platini is restored to his duties as president of UEFA before the Euros, it will be an obvious victory," Wehrli said. "It would underline the attitude of FIFA, who did everything to prevent him from standing for the presidency of the institution.
"If the CAS judges that Michel Platini was maybe imprudent in claiming his money nine years later and it leaves him the eight months [of a ban] already served, we will accept it.
"Our goal is that he might be president of UEFA for the Euros and, if possible, for the two finals of the European Cups for clubs."
While Blatter has been called as a witness by FIFA, among those testifying on Platini's behalf are Jacques Lambert, who was head of the organising committee for the 1998 World Cup, and Spanish FA president Angel Maria Villar, a long-serving member of UEFA's executive committee.
Wehrli said: "A large part of the accusation was to say: 'There was never a contract. In 2011, Blatter bought the non-candidacy of Michel Platini for the presidency of FIFA. That justifies the two million payment and they invented the story of a contract after the fact.'
"Villar will testify that he heard talk of this contract and that Michel Platini never asked the European federations to vote in a certain way."
Wehrli felt Platini had made "an error in judgement" by not obtaining the payment he was owed by FIFA until 2011, but he stressed that the 60-year-old had declared the money and subsequently paid his taxes.