trezeguet was the exact same, and became the highest goalscoring foreign player we have ever signed
merely the fact that such player is in the box, makes defenders nervous, just the fact that there is that one player that if he can grab the ball there, will score, gives the entire team courage to keep pressing forward trough stoppages.
also, when the opponent is having a seriously good defence, or is putting up a wall, its players like this that give it the edge.
remember mourinho's comments on the game against milan. he couldnt care less about any player they'd field, but he feared inzaghi