The Brazil international only signed for the Bundesliga outfit in the summer, after leaving Bayern Munich in the search of more regular first-team football.
Arsenal looked set to capture the 26-year-old, but he decided to stay in the Bundesliga in order to improve his chances of selection for this summer's World Cup.
But Barcelona still seem keen, and a clause in his contract has alerted the Catalan giants.
"It's always good to have your name linked to Barcelona," He told Globo Esporte.
"This is the third time there has been interest from them.
"I have a long contract which includes a buyout fee, and if anyone wants to pay that, they can sign me."