What is the function of a linesman in a soccer match?

The primary function of a linesman, more commonly referred to as an assistant referee in modern terminology, is to assist the center referee in managing the game by signaling for offside infractions and indicating when the ball has gone out of play. This role is essential for maintaining the flow of the game and ensuring that key decisions are made accurately.

When a player is in an offside position at the moment the ball is played to them, the assistant referee raises their flag to alert the referee, helping to enforce the offside rule effectively. Additionally, the linesman signals when the ball leaves the field of play, whether it is for a throw-in, corner kick, or goal kick. This helps the game continue smoothly without interruptions due to missed calls.

While other responsibilities exist in the context of officiating, such as controlling the game clock or making final decisions on fouls, those duties fall primarily to the center referee. The assistant referee's focus remains on the specific aspects of play that occur along the sideline, emphasizing their role as a key support figure during the match.