It will help a lot of people.
I had a provincial tryout, and I feel I played great. You just have to be hungry for the ball (confidence, courage). Every 50/50 tackle I told myself the ball was mine, and guess what, it made the defender completely back down! In tryouts, don't go and try to prove anything to anyone. You're out there to play the game, to have FUN. Relax, don't take it too seriously. (Don't act stupid or anything) But don't worry about mistakes or if you are going to make the team. I went out there that time and I forgot they were tryouts, I was having so much fun. if I did make a mistake, which I did, I didn't worry about it, I came right back at it. It worked out fine, and I scored, so I think it went pretty well. Don't take them too seriously, it just doesn't work.
Also, mental confidence is great. Even if you might not be, in your head before you go out tell yourself you're better then the next guy. And then go out and prove to yourself, while keeping a huge smile on your face. This ALWAYS works for me. Remember, there is no such thing as pressure, it's something you do to yourself, and makes you nervous. so don't worry about it. Coach's will see you if you are playing well, don't try to SHOW yourself to them, and you'll be fine.
And in the wise words of Donald Trump:
"The mind can conquer anything."