Biraghi says he was delighted to put pen to paper on Tuesday.
“I was contacted by the club before the end of last season, I felt their confidence and the desire to return to Florence," Biraghi said at a virtual press conference.
“This was important, and I also wanted to return. The renewal was automatic, the important thing was the desire to start again.
“The agreement is until 2024. There's a long project in the renewal terms, for four years, together with the club and the President, we want to do well."