Assistant Referees, stay in line with the next to the last defender or the ball whichever is closer to the goal to call the off-side. Remember, the player must participate in the play by either interfering, playing the ball or forcing an opponent to run to play the ball before the call is made.

A.R.s must flag fouls not seen by the referee. Expecially on a full size field. Help out the centers. If you see it raise the flag and waive it. Then point in the direction that the kick should be taken.