On the occasion of a goal kick from Team A the coach is instructing his outside mid-fielders to step off the pitch about 1/3 of the way down, proceed in the direction of the kick while still outside the pitch then enter the pitch to make the play. It took me awhile to realize what was going on. After the game I asked the referee if this was leaving the field without permission and she agreed that they weren’t leaving the field to play the ball as allowed. Also note that the player was not reentering the field at the point at which they left. I also contend that this was done to deceive and thus would be considered unsporting behavior.
USSF answer (April 30, 2009):
Players are allowed to leave the field without permission only during the course of play — to avoid obstacles, such as an opponent, and to play the ball in the possession of an opponent on the line.
Players are not otherwise allowed to leave the field of play without specific permission of the referee. Doing so and then re-entering without permission is at least a cautionable offense.
This has nothing to do with trickery or deception. It is, plain and simple, the offense of leaving the field without permission, an act of misconduct in itself.