While we're on the topic of IS and IP...

[PiggSkin]

Good Point LJ...

I would've sworn that this is a foul, but a player isn't replaced until his replacement becomes a player... Since there was no replacement, the 11th guy is still a player...

The key part of 3-7 says, "... and no player shall withdraw and re-enter as a substitute unless ..."

The book doesn't define withdraw, but this player in question is not re-entering as a substitute..

Therefore, in the original question, I would say that the player is guilty of encroachment as soon as the center touches the ball and the player is on the wrong side of the neutral zone... If the player was never on the wrong side of the neutral zone, everything seems to be okay... I can't find a rule to prevent him from stepping onto the field after the snap, either...

Feel free to punch holes in the logic...