​Frenkie de Jong is set to undergo further tests on his knee injury on Friday to determine the severity of the problem and how much time he will miss.The midfielder returned from World Cup 2026 with the problem, and Barcelona are said to be furious at the situation as De Jong played through the pain barrier at the tournament.AdvertisementAdvertisementAdvertisementAccording to Marca, De Jong’s injury will be checked again tomorrow and a statement could be issued to clarify the situation with the Dutchman,The current thinking is that De Jong will miss around four months of action which would be a big blow for Hansi Flick and the player.De Jong’s injury may also have other ramifications. Marc Casado has been linked with an exit but could now stay at the club to cover for the Dutchman.Flick could also look to the club’s youth once again with Tommy Marques, Guille Fernandes and Brian Fariñas currently in pre-season training with the first team and potential options.