The 50-year-old Croatian has been working as FIFA's deputy secretary general and as an adviser to FIFA President Gianni Infantino on strategic football matters since 2016.

He is set to team up again with AC Milan icon Paolo Maldini, the club's newly-appointed technical director with whom he won four Serie A titles and the UEFA Champions League in 1994.

"I will always be grateful to FIFA President Gianni Infantino for the opportunity he gave me after his election in 2016," Boban said.

"True to his manifesto pledge to bring football back to FIFA and FIFA back to football, he had the courage to entrust a former footballer with such a far‑reaching role within the organisation."

During his spell at FIFA, Boban has been involved in many reforms that FIFA claim are set to leave a mark on football history and that have helped to restore the organisation's image.

"I feel really honoured and privileged to have worked on such important projects to take FIFA back to its rightful place, far away from past scandals and a tarnished image," he said.

"Looking back, I feel a real sense of accomplishment about my contribution to these big changes over the last three years.

"I have been entrusted with leading important projects such as the revamp of the FIFA Club World Cup and the successful bidding process for the FIFA World Cup 2026, as well as the revolutionary VAR (Video Assistant Referee) project, which has managed to make the beautiful game fairer and protect its integrity.

"None of this could have been achieved without the support of the President and amazing colleagues who are dedicated to serving the game of football across the globe.

"There may have been some debates along the way, but we have always upheld our motto of 'Living Football' and I will be eternally thankful to everyone."

Following three years in Zurich, Boban is returning to Milan and the club where he spent 10 years from 1991 to 2001 after playing for Dinamo Zagreb.

"It is extremely difficult to leave FIFA, but I followed my heart and my passion when making this decision, as was the case when I accepted the challenge of joining FIFA," he said.

"The people at AC Milan are my family and the city of Milan and Italy are my home.

"I have a burning desire to help this glorious club, which means so much to me, to return where it belongs.

"Zurich now also has a special place in my heart after three wonderful years in Switzerland."

Infantino paid tribute to Boban as a person and professional, noting that his departure represents a great loss.

"I cannot thank Zvonimir enough for everything he has done for FIFA and football over the last three years by our side," he said.

"His dedication to football and enthusiasm are incredible and he has been an invaluable asset for FIFA – nobody embodies football better than he does and he has always worked for the good of the game.

"Many of the positive changes that we have made over the last three years could not have been achieved without Zvone.

"He has shown the same commitment, heart and passion at FIFA that characterised his attitude on the pitch.

"We will miss him a lot at FIFA, but I wish him the same success in his new challenge at his beloved club."

Boban and Infantino attended the FIFA Under-20 World Cup final in Poland on Saturday (June 15), when Ukraine beat South Korea 3-1.

As an 18-year-old, Boban won the FIFA World Youth Championship – the predecessor to the current tournament – with the former Yugoslavian national team in 1987.

He had a decisive role in the victory over Germany in the final, scoring with an unstoppable shot from the edge of the box in the 85^th minute and then converting the winning penalty in the subsequent shoot-out.

Boban leaves FIFA less than two weeks after Infantino was re-elected as President.

Infantino stood unopposed and will serve his first full four-year term through until 2023.

He took over in 2016 after disgraced predecessor Sepp Blatter resigned amid the corruption scandal which plunged FIFA into crisis.

The former UEFA general secretary secured a further four years at the helm by applause after members of the Congress approved a statute change to elect a President by acclamation if there is only one candidate.

Infantino claimed during his opening speech to the Congress that he had turned the organisation from being "toxic, almost criminal" to "what it should be – an organisation that develops football, an organisation that cares about football".

He insisted FIFA had moved on from its scandal-tainted past, despite a spate of officials being banned, including Council members, since he replaced Blatter.

Boban and Maldini rejoin Milan at a low point for the seven-time European champions, who finished sixth in Serie A last season and extended their failure to qualify for the Champions League to six years.

UEFA is investigating Milan's finances and has threatened the club with a one-season ban from European competitions if it fails to meet targets by June 2021.