He currently plays for Racing Santander, wearing the number 3 shirt. He plays primarily as a Defender. His preferred foot is Left. His current market value is estimated at 900K €.

His most recent move was a from Rayo Cantabria to Racing Santander on 2023-12-31.

Throughout the Copa del Rey 2025-2026, Mario García Alvear featured in 4 matches, averaging 2.8 tackles, 1.5 interceptions, and 4.8 clearances per game, while blocking 0 shots per game.