Catching the football is a combination of extreme concentration and controlled relaxation.  You can’t catch the football if you don’t concentrate but you also can’t catch the football if you are stiff as a board when it hits you in the hands!  A great player is relaxed enough that when the ball hits him in the hands it sounds like a basketball hitting nothing but net!  Being in the zone best describes a player who catches everything thrown his way.  He is in that zone that is a combination of concentration and relaxation.  Here is great article on how to catch a football.