Gattuso could stay at Milan for 10 years, says Mirabelli
Former Milan favourite Gattuso was promoted from his role with the club's youth teams when Vincenzo Montella was sacked in November, despite a largely unheralded coaching career to date.
The Rossoneri lie eighth in Serie A and are unbeaten in 2018, leaving Mirabelli suitably impressed.
"When we gave him the Milan bench he was considered a gamble by many but we chose Gattuso because we thought he was a coach able to replace Montella and stay for a long time, even 10 years," he told reporters
"He is proving to be a great coach. We are not working to think of a substitute."
46 - Since Gennaro Gattuso's appointment as manager (last 7 match-days), AC Milan have fired the most shots on target in Serie A (46). Rise. pic.twitter.com/W6HkYIUOIl
— OptaPaolo (@OptaPaolo) January 24, 2018
Milan undertook a significant overhaul of their playing staff during the close season after being taken over by Li Yonghong's Rossoneri Sport Investment Lux company.
Not all of the high-profile arrivals have hit the mark, with Portugal international Andre Silva yet to score in Serie A and fellow striker Nikola Kalinic netting a solitary goal since October.
Patrick Cutrone's emergence has done something to ease the goalscoring burden but Mirabelli believes a youthful squad is on the right track.
"Although Andre Silva is not giving what we expected, we all believe he can become a world-class player," he said.
"[Hakan] Calhanoglu has also been criticised, but now he has responded well.
"Kalinic is recovering; Cutrone is a beautiful discovery and we must not put any pressure on him."
Mirabelli added: "It is not yet time to regret. It is true that we have lost some time but there is still a long way to go.
"We know we wanted to build a young team that we hope will lay the foundations for a good future. Our average age is low and we have many Italians, which is why we are satisfied.
"We are trying to get back to the enthusiasm that was there at the beginning of the season."