The Catalan club are looking for a goalkeeper with the ability to challenge number one Marc-Andre Ter Stegen.
Current deputy Neto only joined from Valencia a year ago, costing Barca an initial fee of €26m.
But because of their financial issues, Barca are reportedly open to offers for the Brazilian.
21-year-old Maximiano has become a regular for Sporting since December, establishing himself as their first choice shot-stopper.
According to A BOLA, Barcelona have a definite interest but have not yet made any moves to sign Maximiano.
However, they add that ‘it is likely’ that there will soon be progress with Barca’s interest.
A transfer fee of €16m for Maximiano is spoken of in Spain. In the meantime, Sporting are working on a contract renewal for him.