The Unify League is a breakaway league proposed in 2021 to rival the traditional UEFA Champions League.
Spalletti’s appointment came three days after former manager Tudor was sacked by the club, following Juventus’ 1-0 defeat to Lazio during the weekend.
Real Madrid hosted French side Olympique Marseille, with Xabi Alonso avoiding a debut defeat thanks to Kylian Mbappé.
Pogba was said to have made some “significant sacrifices to seal the deal” and facilitate his return to football after his contract with Juventus was terminated in 2024.
The 31-year-old was provisionally suspended from football-related activities in September 2023.
Juventus travel to RB Leipzig in the Champions League on Wednesday before they host bottom side Cagliari in Serie A on October 6.
“The club wishes Massimiliano Allegri good luck in his future endeavours,” it said.
Ronaldo claimed he was owed more than £17m by Juventus.
His lawyer had rejected a plea deal with the hope his client would receive less punishment.
In a TV interview, Mr Alves initially denied knowing the victim but later backtracked.
