Larsson has spent the last six seasons at the Stadium of Light but with the club being relegated to the Championship, he is likely to leave the Black Cats.
According to reports in Italy, he may be offered the opportunity to link up with Fiorentina once his contract expires at the end of the campaign.
The 31-year-old has spent the last few years as a first-team regular at the North-East strugglers, but he has earned 88 caps for Sweden since 2008.
Larsson has scored 14 goals in 200 appearances for Sunderland since leaving Birmingham City on a free transfer.
Fiorentina currently sit in eighth position in Italy's top flight, leaving them with work to do to qualify for next season's Europa League.