Whats the best way to avoid muscle injury when playing soccer?

Hydration, protectio. 2 hours or more before the game eat a good meal with adequate proteins etc. During the game small sips of gatorade, do not overload yourself with fluids. Protect yourself with knee guards long socks etc. Stretch and warm up before the game. Play smart, a avoid injury by opposition and to others. If a foul play is anticipated just get rid of the ball, quick short passes, do not hang on to the ball.

Prepare. Warmup properly and drink plenty of liquids.