He currently plays for Athletic Bilbao B, wearing the number 7 shirt. He plays primarily as a Forward. His current market value is estimated at 1000K €.

His most recent move was a from CD Basconia to Athletic Bilbao B on 2024-07-01.

In the Primera Federación 2025-2026 season, Asier Hierro scored 2 goals and provided 0 assists across 10 appearances, averaging 0.2 goals per game with 13 shots attempted and 7 on target.