Where I'm from that changed me

I am from warm up's and drills,
from soccer balls and bruises everywhere.
I'm from the dirt on someone's knee.
I am the broken limbs on a tree.
When you work so hard,
 your legs start to feel like gummy worms.
I'm unstoppable.
The ball under my feet.
The ball is a prison under my feet.
So fast I can't be caught,
like a prisoner that cant be caught.
I'm a soccer player.
Ready for action.