He currently plays for Sant Andreu, wearing the number 24 shirt. He plays primarily as a Defender. His current market value is estimated at 25K €.

His most recent move was a from UE Sant Andreu U19 to Sant Andreu on 2024-07-01.

Throughout the Spanish Segunda División RFEF 2025-2026, Pablo Santiago Casellas featured in 23 matches, averaging 0.1 tackles, 0 interceptions, and 0 clearances per game, while blocking 0 shots per game.