The 28-year-old has spent three years at the Stadium of Light, and has remained an integral part of the squad, scoring the crucial winner in the Black Cats' surprise victory at Manchester United on Saturday.
However, the Sweden international is out of contract in the summer and with no new deal on offer just yet, Larsson has revealed that he may have to move on.
"My contract expires and it might imply that I play somewhere else this autumn," Larsson told Sportbladet.
"I try to avoid being led by my emotions and focus on the remaining matches.
"Afterwards, I will see what happens."