The Premier League side would have to find £13.5 million to stand any chance of luring the full-back, who is also attracting interest from Serie A, away from Camp Nou
Barcelona would demand around £13.5 million for any deal involving Sunderland-linked defender Aleix Vidal, according to Mundo Deportivo.
The Black Cats are one of a number of clubs said to be keeping an eye on the 27-year-old full-back, with AC Milan, Napoli, Inter Milan and Granada also in the running.
It had earlier been suggested by Sport that any of the interested parties could see a loan switch sanctioned with a view to a £11.65m permanent move.
But it now appears that they would have to dig a little deeper in order to land a man Barca snapped up from Sevilla in 2015.