Barcelona would be forced to pay an additional £89m in order to sign any Liverpool players before 2020, it has been revealed.
The Catalan giants have been linked with a move for Roberto Firmino, just a year after taking Philippe Coutinho from Anfield to Camp Nou last January.
However, Liverpool included a clause in that deal to ensure that Barca could not come knocking again in the near future, with the two clubs agreeing that the La Liga champions would not sign another Liverpool player until 2020.
Barcelona could still try to sign Liverpool players - including Firmino - but they would be forced to pay an additional premium of £89m on top of the agreed sale price.
Such a package would likely take Firmino's price beyond £160m, discouraging Barca from moving for the Brazilian or any of his teammates before 2020.
Liverpool have lost Javier Mascherano, Luis Suarez and Coutinho to Barca in the past decade, with the latter joining in a deal which could rise to £142m.
