Mascherano won 147 caps for Argentina, second only to Lionel Messi
Former Barcelona and Liverpool player Javier Mascherano will take on his first coaching role when he takes over as Argentina Under-20 boss in January.
The 37-year-old, who won 147 caps for Argentina and served as his country's captain, will replace Fernando Batista.
Mascherano called time on his playing career in 2020 having last played for Estudiantes.
A versatile defensive player, he won five La Liga titles and two Champions Leagues in eight years at Barcelona.
He started his career with River Plate and moved to West Ham in 2006 following a spell with Corinthians.
Signed by Liverpool in February 2007, he helped the Reds reach the Champions League final that year before moving to Barcelona in 2010.
In 2014, he played every minute of Argentina's World Cup campaign as they lost to Germany in the final.