Argentina attacking midfielder Manuel Lanzini has picked up an anterior cruciate ligament injury in training and will miss the World Cup.
Depending on the seriousness of the damage to his knee, the 25-year-old may also miss the beginning of West Ham United's 2018-19 Premier League campaign.
Lanzini was expected to start Argentina's opening Russia 2018 fixture against Iceland next week after forcing his way into manager Jorge Sampaoli's plans.
However, a statement on La Albiceleste's Twitter page on Friday revealed that the West Ham ace - touted as a target for Liverpool this summer - will no longer be part of the 23-man squad.
"Manuel Lanzini suffered, in today's morning training, the rupture of the anterior cruciate ligament of his right knee," the translated statement read.
Argentina have already had their World Cup preparations disrupted by the cancellation of a friendly against Israel and the loss of first-choice keeper Sergio Romero to injury.