A six-goal, one assist campaign season in 2015-16 for Genoa has been followed up by Suso tallying 13 goals and 16 assists for the Rossoneri over the past two campaigns.
His six goals and seven assists this season contributed to the team's success, but Milan failed to challenge for a Champions League place after spending heavily, finishing sixth in Serie A.
In addition, the Rossoneri are set to miss out on Europa League football after UEFA banned them in relation to a breach of Financial Fair Play and licensing regulations, though the club are appealing to the Court of Arbitration for Sport.
There has been speculation that Suso, under contract until 2022, could depart - potentially to city rivals Inter - but Mirabelli has made it clear that no such deal will happen, though he did admit Suso does have a release clause for teams outside of Italy.
Speaking at a news conference, he said: "I can assure you there's no chance whatsoever he's going to Inter.
"It's true he has a release clause valid for non-Italian clubs, but he has always said he wants to stay here with us and we are relying on him."
Speaking in May, Suso had said he was content to stick with Milan as long as they continued to show ambition.
Despite the possible lack of European football next season, Milan has been busy making additions for the coming season.
Former Barcelona midfielder Alen Halilovic joined the club after a two-year loan with Hamburg, while Pepe Reina and Ivan Strinic have arrived on free.