Signed on loan from Aston Villa in July 2025, the Argentine defensive midfielder arrived at Benfica after a formative journey across four European leagues.

Barrenechea took his first steps at Newell's Old Boys before moving to Switzerland with FC Sion in 2019. He joined Juventus in 2020, developing with the reserve side and making his senior debut for the Bianconeri in a UEFA Champions League match in November 2022. A loan at Frosinone in 2023/24 brought him regular Serie A minutes, and in the summer of 2024 he transferred to Aston Villa, spending the following season on loan at Valencia.

At the Estádio da Luz he took the number 5 shirt and quickly became a regular presence in midfield, valued for his physical presence and ball-winning. He won the Supertaça Cândido de Oliveira in his first months at the club.