The Inter loanee brought an end to his temporary stay at the London Stadium with another solid showing, rounding off a string of fine performances for the Hammers during their 3-1 win over Everton on the final day of the season.
Since then, Red Devils boss Jose Mourinho has been outspoken regarding his appreciation of the 25-year-old, who will be heading to Russia this summer as part of Portugal's international set up.
Mourinho on signing Joao Mario: “Why not? Joao just had to settle down. He is a player who thinks and acts quickly, he has recovered his speed of thought and execution, intensity and aggressiveness. I liked it in every game more.” pic.twitter.com/vOPwvxzT0M— Ironwork Tours (@IronworkTours) May 17, 2018
And according to Italian news outlet FcInterNews.it, United have been offered the chance to snap up the midfielder by super agent Kia Joorabchian this summer - with the Nerazzurri setting their price at around £22m to £26m to strike a deal.
Despite the Serie A giants being prepared to wait until how Fernando Santos' side fare at the World Cup, a season-long loan with an obligation to buy has also been mooted.
However, Mourinho is not the only boss Joorabchian is said to be in contact with, with La Liga outfit Valencia as well as West Ham also in the frame.
It is thought that should the east Londoners land their key managerial target, former Manchester City boss Manuel Pellegrini, in the coming days, and the Chilean gives the green light, Mario may well be heading back to the London Stadium after the player admitted his happiness during his spell at the club.
During his 13 games after the January transfer window, the Portuguese midfielder scored two goals and provided one assist for David Moyes' men in their successful bid for Premier League safety.