Manchester United will have to overcome Barcelona if they're to sign Atletico Madrid midfielder Saul Niguez.

Saul has been linked with United this week as a potential replacement for Paul Pogba.

But El Mundo Deportivo says Barcelona have first refusal on Saul, should he ever seek a move away from the club.

The Spain international has a €150m release clause but Barca made a verbal agreement with Atletico when they sold David Villa to the club in 2013 that they would be the first option for Saul.

Saul scored Spain's first goals in their recent Nations League victories over England and Croatia.