Porto and Benfica are both battling to sign Real Sociedad goalkeeper Geronimo Rulli this summer, according to reports.
El Mundo Deportivo claim that a loan with an option to buy with Porto had been close to completion but that this is no longer certain.
Earlier this month, Diario AS cited reports in Portugal that the Argentine shot-stopper will join the Dragons after making 29 appearances for La Real last campaign.
The 27-year-old first moved to the Basque club in the summer of 2014 having previously been on the books of Estudiantes and Deportivo Maldonado, making 180 first-team appearances for the club.
It is said that the Portuguese giants are hopeful of signing a goalkeeper to add competition for established number one Iker Casillas, who suffered a health scare in training just two months ago.
The report cites former Spain international goalkeeper Casillas as once saying that Rulli was one of his favourite shot-stoppers in the Spanish top flight.
Last season, La Real rejected a €15m approach from Napoli for the goalkeeper and it is likely that they will demand a minimum of €20m for any summer move.
The move would leave Miguel Angel Moya as the first choice goalkeeper at Real Sociedad.