Philadelphia Union's tactical formation is set by head coach Jim Curtin and can change from match to match based on the opponent, available players, and tactical objectives. Common MLS formations include 4-2-3-1, 4-3-3, 3-5-2, and 4-4-2.
MLS coaches increasingly employ tactical flexibility, adjusting formations within matches and between games. Philadelphia Union's preferred system reflects the coach's philosophy and the strengths of the players available.