Zlatan Ibrahimovic brought the curtain down on a long, trophy-packed career on Sunday when he unexpectedly announced his retirement from football.

Veteran striker Ibrahimovic revealed his decision to quit the game during an on-pitch ceremony following AC Milan's 3-1 win over Verona which ended their Serie A campaign.

"It's the moment to say goodbye to football, not just to you," said Ibrahimovic on the San Siro pitch.

"There are too many emotions for me right now. Forza Milan and goodbye."

The 41-year-old had been expected to simply bid farewell to Milan fans after his departure from the seven-time European champions was announced on Saturday.

He returned to Milan in late 2019 for a second spell after a previous two-year period in which he won the Serie A title in 2011.

"The first time I came here you gave me happiness, the second time you gave me love," said Ibrahimovic.

"You welcomed me with open arms, you made me feel at home, I will be a Milanista for the rest of my life."

Ibrahimovic was a key figure in Milan's resurgence to the top of Italian football after his return to the club, helping to bring them back from the doldrums and eventually win the Scudetto last season.

"I used to be scared when journalists asked by about my future, but now I can accept it, I'm ready," Ibrahimovic told reporters after his announcement.

"I've been doing this all my life, football made me a man. It allowed me to know people I otherwise would never have known, I've travelled the world thanks to football. It's all thanks to football."

Over the course of his career Ibrahimovic won league titles in the Netherlands, Italy, Spain and France, although his only major European trophy was the 2017 Europa League with Manchester United.

Making his announcement at the San Siro was appropriate as he also won three straight league titles with Inter Milan between 2006 and 2009 before a turbulent spell at Barcelona.

His retirement comes after a season in which he has hardly featured for Stefano Pioli's side after being plagued with injuries, returning in February following surgery on his left knee in May.

In July he signed a deal which netted him around one million euros (US$1.02 million) in fixed salary, with large bonuses linked to appearances and achievements.

But after agreeing that deal the 41-year-old only started one match and netted once for Milan, a 3-1 win at Udinese in March in which he became the oldest goal scorer in Serie A history.

He then picked up a calf injury in a pre-match warm up in April and ended his career sidelined, scotching rumours that he was set to move to Monza and targeting Euro 2024 with Sweden. (AFP)