Barcelona are not allowed to sign players from Liverpool for a total of three years due to an agreement made when Philippe Coutinho swapped Anfield for the Camp Nou earlier this year.
Coutinho made the move to Catalonia for £142m, eclipsing the £73m that Barcelona paid to sign Luis Suárez shortly after the 2014 World Cup.
Frustrated that the club's best players were simply being poached by the La Liga giants, radio station Cadena Ser (via AS) claim that Liverpool demanded a clause to be included in Coutinho's move which would prevent their best players from making the same move in the near future.