Leandro Paredes has sustained a hamstring injury just over two weeks before Argentina begin their World Cup defence.
Paredes was part of the squad that lifted the trophy in Qatar in 2022, scoring a penalty in the shootout success against France in the final.
Three-and-a-half-years on, the Boca Juniors star has been named in Lionel Scaloni's 26-man squad for the tournament in Canada, Mexico and the USA.
However, Argentina are now sweating on Paredes's fitness following the news that he has suffered an injury.
Paredes suffers injury blow ahead of World Cup
According to journalist Martin Arevalo, the 31-year-old has sustained a hamstring issue that will prevent him from featuring in Argentina's two warm-up games.
La Albiceleste will face Honduras at Kyle Field on June 6, before they take on Iceland at Auburn's Jordan-Hare Stadium on June 10.
Argentina will then kick off the 2026 World Cup with a clash against Algeria in Kansas City on June 16.
An estimated recovery time of three weeks means that Paredes faces a race against time to prove his fitness for the opening game.
Scaloni's central midfield options
While Paredes has 77 international appearances to his name, there is no guarantee he will be a certain starter at the World Cup even if he proves his fitness ahead of the first game.
Liverpool's Alexis Mac Allister, Chelsea's Enzo Fernandez and Inter Miami's Rodrigo De Paul are likely to be at the forefront of Scaloni's central midfield plans.
There is a possibility that Scaloni could deploy all three or pick two to feature in a 4-2-3-1 or a 4-4-2.
The Argentina boss can also call upon Giovani Lo Celso, Exequiel Palacios and Valentin Barco as his alternative midfield options.