In the sport of association football, a defender is an outfield player whose primary role is to stop attacks during the game and prevent the opposition from scoring.
Centre-back John Terry (right) closely marks centre-forward Didier Drogba.
Edwin van der Sar, pictured playing for Manchester United during the 2010–11 season, is considered to be one of the pioneers of the sweeper-keeper role.
Paolo Maldini marking a player during a friendly match.
Wing-back Caitlin Foord (right, wearing no. 9) in action with Australia against China at the 2017 Algarve Cup.
In association football, the formation of a team refers to the position players take in relation to each other on a pitch. As association football is a fluid and fast-moving game, a player's position
Program for an 1887 game between Blackburn Rovers and Sheffield Wednesday. The players of both teams are arranged in 2–3–5 formation.
3–5–2 formation
3–6–1 formation