Can the player from the opposing team lay down on the ground in the path of a player to try and impede him? Is it a penalty if he does?
USSF answer (June 11, 2009):
Surely you jest! We find it hard to imagine a player lying down in the path of an opponent, much less trying to hinder or delay the opponent that way. Way too dangerous a thing to do. However, if a player were indeed crazy enough to do it, the foul would be playing in a dangerous manner, punishable with an indirect free kick for the opposing team at the place where the foul occurred. Or, as you suggest in your question, it could also be “impeding the progress of an opponent” (particularly an opponent so lacking in athletic ability as to be unable to jump over someone on the ground).