Álvaro Carreras spent four years at Manchester United without playing a competitive first-team match, gaining his senior experience on loan at Preston North End and Granada. He joined Benfica on loan in January 2024 and impressed sufficiently for the club to make the transfer permanent in May of that year.

A left-footed left-back, unusually tall for the position, he is an attacking full-back who overlaps high up the pitch and contributes goals from wide areas.

He was among the first names on the team sheet in 2024/25, making 52 appearances in all competitions and scoring four goals, three of them in the league. He was named the Primeira Liga's Defender of the Month in March 2025 and was selected in the Primeira Liga Team of the Year. He left for Real Madrid that summer.

He has played for Spain at under-19 and under-21 level.