Leão, 26, has been scouted by United representatives on multiple occasions in recent weeks — including during Milan's 0-0 draw with Juventus on April 26.
The repeat attendance signals a serious, rather than exploratory, level of interest. The Gazzetta dello Sport also reported that Manchester United have contacted his agent Jorge Mendes, who represents a number of players across both clubs, to gather detailed information.
The winger has accumulated 80 goals and 65 assists in 288 appearances for Milan since joining from Lille in 2019, but has been below his best this season with 10 goals and three assists in 28 appearances. His contract runs until June 2028, giving Milan leverage — but the failure to secure Champions League football next season has softened the club's stance on a sale.
United are in the market for left-sided attacking reinforcements heading into their first Champions League season since 2023/24. Their primary target is Aston Villa midfielder Morgan Rogers, valued at around €100million, with Leão identified as the most realistic premium alternative.
The arrivals of Matheus Cunha and Bryan Mbeumo have not fully filled the need for a direct, pace-based winger on the left flank.
A potential swap deal involving Joshua Zirkzee or Manuel Ugarte, both of whom are of interest to Milan, has been discussed as a way of reducing the cash outlay. United are unwilling to commit to the full €50million in cash alone given their financial constraints under INEOS's ownership model.
Whether AC Milan can finish in the top four on the final day against Genoa will also shape how strongly they hold their price. A Champions League finish removes some of the urgency to sell immediately.