The Belgian winger, born in 2004, is due in Milan around midday for his medical after agreeing to join Rúben Amorim's squad, following the earlier arrivals of Gonçalo Ramos and Mario Gila.
According to Sky Sport, the deal is worth €45 million in guaranteed fees, plus a further €20 million in bonuses — making it the second most expensive transfer in Milan's history behind Ramos.
Moreira's versatility across the frontline was central to Milan's decision to move for him, with the left-footer capable of playing on either flank or in a central attacking role behind the striker.
He made 42 appearances for Strasbourg last season across Ligue 1, the Coupe de France and the Conference League, scoring five goals and providing nine assists, form that also earned him a place in Belgium's World Cup squad this summer.
AC Milan's business, though, is not entirely one-way. While the club continues to strengthen going forward, Juventus have Milan's own defence and midfield in their sights as they look to add further reinforcements of their own.
According to Sky Sport, Juventus's Giovanni Carnevali and Frederic Massara — despite already bringing in Jhon Lucumí — are looking at Fikayo Tomori as a possible option in central defence, should Milan decide to sanction his exit. The Bianconeri are not stopping at a defender either, with the same sources naming Youssouf Fofana as a target to strengthen Luciano Spalletti's midfield.
Neither Tomori nor Fofana appears close to leaving Milan at this stage, with the club having shown no obvious inclination to sell either player as it looks to build a settled squad under Amorim following a summer of significant investment in attacking areas.