Alongside midfielder Fiorini, goalkeeper Cieran Slicker and forward Ben Knight have both signed new deals at the club.
Fiorini (19) spent last season on loan at NAC Breda, scoring 5 goals in 32 appearances for the Dutch side as they reached the play-off finals.
The Scotland youth international's deal will keep the midfielder at the club until 2026, and his development will continue this season at League One's Lincoln City.
Knight (19), arrived at Pep Guardiola's side in 2018 for a £1 million fee. He helped City's Under-23s win the league last season, registering a goal or assist every 92 minutes on average - his contract extension will keep him at the club until 2025, but it is not yet known if there are plans to loan the youngster out.
Finally, Slicker (18) has signed a one-year extension to keep the 'keeper at the club until 2024. A fellow youth international with Fiorini for Scotland, Slicker has been at the club for a decade and made 14 appearances for City's successful Under-23s in the 2020/21 season.
The deals have been officially announced on the Manchester City website. City fans will be hoping for further announcements concerning the first-team.
Recent rumours have suggested Riyad Mahrez could be in line for a new contract, but most pressing of all is defender John Stones, with the England international approaching the final year of his deal.
Nevertheless, a three-year deal is said to be close to agreement, and there is no signs that Stones' future lies anywhere else but the Etihad Stadium for now.
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