Gianluigi Donnarumma and Paris failed to reach an agreement and joined Manchester City at the end of this summer's transfer window with a transfer fee of 30 million euros.
Haaland also posted a photo of him embracing Donaruma through social media, and warmly welcomed the powerful new player: "Welcome, Gigio (the nickname of Gianluigi)!"
26-year-old Donaruma plays as a goalkeeper, currently turning 40 million euros in Germany, and just helped Paris reach the triple crown last season.