The Rossoneri's proposal for the 19-year-old, Rúben Amorim's top target for the attacking midfield role behind the striker, was structured as a loan with an obligation to buy set at €40m.
Arsenal have so far not engaged with the offer, according to Gazzetta dello Sport, though Nwaneri remains Milan's primary target for the position, with the player having spent the second half of last season on loan at Marseille. Alternative options include Midtjylland's Dario Osorio, while interest in Roma's Matías Soulé has cooled in recent days.
AC Milan's need for a wide attacking midfielder stems in part from confirmations elsewhere in the squad. With Yunus Musah, Samuele Ricci and Filippo Comotto all having convinced Amorim during pre-season, a further addition in central midfield now looks less urgent, freeing the club to focus resources on other areas of the pitch.
That has turned attention to the flanks, where Milan are exploring several separate options tied to the club's own outgoing business. Zachary Athekame's loan move to Lyon is close to being finalised, and Pervis Estupiñán could also depart, prompting Milan to look at reinforcements even while Alexis Saelemaekers, Samuel Chukwueze and Davide Bartesaghi remain in the squad.
The most advanced interest is in Nicola Zalewski, the Poland international who arrived at Atalanta from Roma just a year ago but whose path has narrowed under new head coach Maurizio Sarri; his valuation sits between €15m and €20m, with the Italian-born wing-back offering the versatility to play on either side. Milan have also been offered Lazio's Nuno Tavares, though there are reservations about his fitness record, while on the right flank the club is monitoring Fiorentina's Dodô, whose contract situation — just one year remaining — could make him available on favourable terms.
The two search efforts reflect Amorim's broader demands this summer: the Portuguese coach has asked owner Gerry Cardinale for at least three further reinforcements before the window closes, with sporting staff including Hendrik Almstadt, Bobby Gardiner and Tiago Estêvão working to satisfy the request regardless of the pace of departures elsewhere in the squad.