And Julio Cesar says the current Old Trafford boss's "heroic" achievements at San Siro mean his place in hearts of Nerazzurri fans is secure.
"Mourinho was more than a father to me when I was at Inter," the 38-year-old told ESPN.
"In only two years, Mourinho and his staff helped win everything. Inter contracted Mourinho to win the Champions League. Inter had success in that period winning Serie A, but the Champions League was different. The club had not won it for 42 years. Within two years, Mourinho had won it. It was a heroic win.
"That Inter team and Mourinho will be in the hearts of Inter supporters forever."
Although the veteran keeper is still playing at Benfica, his career with Brazil's national team came to an end in 2014 after they suffered a 7-1 defeat to Germany on home soil in the World Cup semi-finals.
Cesar is sure he will never be able to live the defeat down, and believes it all came down to a crucial 15-minute period.
"Unfortunately, I'll have to reply to this question for the whole of my life," he added. "It's a situation that, until now, the people who played could not find an answer to what happened.
"We met a very strong team who had been prepared since 2006 to win this World Cup in 2014. Germany had been building this team for a long time, their coach explained that. I respected this Germany team a lot. They were very well organised and every player contributed to making them a great team.
"We lost our concentration for 10 or 15 minutes. In that short time we were penalised by the team who would win the World Cup."
This year, Brazil finished top of South American qualifying for the 2018 World Cup in Russia and Cesar believes the Selecao have a bright future under current coach Tite.
"He's given an identity to Brazil. After the World Cup in 2014, Brazil need to find its way again; Tite understood this," he said.
"He worked hard, got Brazil playing well. We were very strong in the qualifying group; a very tough qualifying group. Losing only one game from 18 when you play all those really strong countries is fantastic. Every other team lost at least four games and this Brazil team is respected around the world."