High School Baseball Coach Striving To Be Christ-Like

Hey everyone. With the help of the Lord, and others, I recently graduated from East Tennessee State University with a degree in Special Education. I am praying for a job in my hometown, if that is the Lord's will for my life. I ask that you also pray to that extent. Next spring will be my second season as a varsity assistant baseball coach, and I am currently the head coach of our high school summer team. I am praying, learning, and trying to follow the Lord's leading as a coach.
I am by nature a disciplinarian. I believe in paying attention to detail, and hard work on the ball field. I received a lot of criticism from parents who do not claim Christ, and parents of children who were either lazy, and/or had bad attitudes. I know our methods are correct, because I know we have a top of the line baseball program, and an excellent coaching staff who gives college level instruction to high school players. However, the criticism I took caused me to look myself in the mirror and evaluate the way I do things. I know that my number one priority has to be being a Christ-like example to young people. If I am a great "baseball man", but do not show Christ, what have I done? Nothing! I am re-reading Coach Tony Dungy's book, Quiet Strength, as well as other materials on him, and am amazed that he doesn't raise his voice or yell. I would love to ask him how he does it. I know discipline and hard work are great, because the Bible speaks often of both. I also know that thinking in terms of the team, as opposed to thinking of self, are also Christ-like qualities that players should possess. My question is this, what about raising my voice? I mean if I have spoke to a player as a young adult after he has done something unacceptable, and told him that it will not be tolerated, and he does it again, what am I to do? I feel the enemy, Satan, is telling me I am hurting my testimony as a coach. I am really struggling, because I am not by nature, like Coach Dungy. I am not naturally laidback. I show my emotions. Please do not misunderstand me, I do not cuss at all, and I would never try to humiliate a kid, but some have questioned my faith because I have high standards. Some think I am not a good Christian because we "get on" the boys. I think the game of baseball can teach many life lessons. I also know we expect more out of the boys, many times, than their parents do. Parents want to look over many things, were we expect a commitment to excellence. I am kind of rambling now, but I would love some prayerful, considerate replys.