Top European clubs are growing increasingly fearful of losing players to the Saudi Pro League in September when they are powerless to replace them.
As Mail Sport highlighted in June, clubs in Saudi Arabia are able to sign players until September 20, meaning the English top flight will be affected for three weeks after the Premier League's transfer window closes on September 1.
And there is fear in Premier League boardrooms that they will be effectively ambushed in this period, with Pro League clubs able to offer salaries that cannot be matched anywhere else in the game.