too close to the line?

[afsst]

Everyone not on the line must be in the backfield. To be in the backfield a player must be positioned so that no part of his body penetrates the plane that passes through the waist of the nearest lineman other than the snapper. One player can be in this zone with his hands in position to receive the ball if it is snapped between the snapper's legs (but he doesn't have to receive the snap).