In a cricket match, why does a player lower his hands slightly while catching the ball?

In a cricket match, the player lowers his than to increase the time in which the high velocity of the ball decreases to zero. by doing so, the momentum of the ball is reduced. If he will not do that then a very large momentum will be produced and after catching the ball, it will come to zero suddenly, and the player would require a large force to catch the ball, and due to the large impact of the ball, the palm of the player may hurt.