Deco joined Barca from Porto in 2004 after helping the Portuguese side win the Uefa Cup, Champions League and domestic league titles.
The 30-year-old won two league championships with the Catalan giants, and was part of the team that beat Arsenal in the Champions League final in Paris in 2006.
However, a series of injuries have hampered Deco's season, contributing to just 14 La Liga starts in Barcelona's campaign.
Reports suggest he is one of a number of big names who could exit the Nou Camp this summer, with Ronaldinho, Samuel Eto'o, Lilian Thuram, Eidur Gudjohnsen and Thierry Henry all mentioned as possible departures.