“To look for the third man is, for example, that the central players have the ball and one of them is always open because you always have one player more than opposing strikers. In that case, Puyol has the ball and goes up, up and up until a defender challenges him. If the defender who tries to stop him is my marker, then the third man happens to be me! If it is Iniesta's marker who moves to challenge Puyol , then Andres is the third man. And so we seek superiority in any area of the field. You make a three against two, you win and you have the third man. We advance positions up the field”. - Xavi Hernández
Taken from https://www.developingthefuture.club/post/2019/07/04/positional-play-the-third-man-concept