If you are practicing hard and grinding all day just to have playing time then show what you did on practice.Some players are practicing hard but the moment their coach call them on the bench and give them an opportunity to help the team, they are not doing what they did on practice. Maybe its because of pressure, maybe its because they don't want to make mistakes that will make it harder for the team. So what is the use of the hours that they burn during practice?, what is the use of the sweats that their skin secrete while doing some reps? If you will not do what you did on practice then don't practice anymore.
Some guys are very good at practice but very bad during the actual game. The only difference between practice and the actual game is the environment and the opponents. The crowd will add a lot of pressure and so your opponents does but the one who will perform is still you and no other, so never change what you did on practice, the way you feel, the way you move your body and the way you feel confident. If you are practicing to show greatness then show it. Even if not on games, if you are practicing something to become better and wants show the world that you can do something then show it, never be shy and never waste the time that you put on practice, even if you are not a star player or someone popular. Once you practice and work hard, you have the right to show it in real life.