1. Warm up well every start of training and games, entering or re-entering the match as a sub,  and every half-time of games.  A cold body is more likely to get injured. Your first sprint or shot should not be in the game!
2. Foam roll or use self-myofascial release with a soft ball or a trained person in anatomy who can get in on your muscles. For soccer players,  smart areas to focus on are quads, groins, and calfs.  I would not suggest deep tissue the day of a game or even the day before a game, but at some point in the week it is a good idea to get worked on.  If you have an nagging injury or pain but can still play, deep tissue on the site of pain  prior to training and games is recommended.
3. Spend time stretching after training and games. This will reduce recovery  time and maintain muscle length.  Flexibility helps prevent injuries,  static stretching before matches does not.  Do we understand the  difference? Save your static stretching for times NOT before training and games. When you do stretch, don’t go through the motions, work on achieving greater range of motion.
4. Strength train! The stronger you are through various ranges of motion the better. Multi-directional lunge variations are great (barbell on back, dumbbells in hand, whatever!), pistol squats, step ups, rdl variations, ankle exercises with bands, knee flexion exercises like Nordic hamstring curls or glute-ham variations are great for preventing knee injuries…simply expose the body to tension with full range of motion strength training exercises.
5. Medial collateral knee injuries that happen in tackles with the inside of the foot can be prevented by going in hard to tackles and by kicking the heavy back or a heavy  padded medicine ball. This prepares the knee for the stress.
6. Body conditioning exercises like purposely banging shins enhances bone density and prevents injury.  Same with knees to the thigh. 
7. Stay hydrated! A dehydrated body is far more likely to fatigue and get injured. Less fluid is bad.
8. Eat a healthy diet and make sure you get enough protein and healthy fats. Omega 3 supplementation is suggested for inflammation.
9. Avoid gluten (wheat protein found in breads, pastas, baked goods) as it causes inflammation.
10. Always play hard and never take a day off from physical challenges.  Be the guy/gal who goes too hard, not the opposite. You must protect yourself at all times because no one else will. 

 Deciding Whether or Not To Play with Injuries

• Bruises and Contusions:

This comes down pretty much to pain tolerance. A bruise will get worse if it gets hit again, but that is pretty much it. Warming up very well, and seeing how you feel and move. If you have to limp drastically you are probably better off not playing just yet as you will be a liability to your team, play poorly and show poorly for yourself (never a good feeling), and you will rely excessively on certain muscles creating a possible imbalance and of course increasing the likelihood of injury somewhere else.

• Sprains of the knee and ankle

The ligaments and tendons are lengthened and the muscles surrounding the injury are probably over-active as a protective mechanism.  You can re-injure sprains easily so be careful and make sure you are strong.  The same limping principle from above applies here.  Taping will help, but I always refrain from taping the ankles unless it is absolutely necessary as you want them to have mobility.  If you can’t move the ankle you will move somewhere else and that usually means the knee.  The knee is a hinge joint so that can lead to a nasty injury. Tape the ankle just enough to not re-injure it.  That will be hard because we can’t always predict what will happen in soccer.  Knees you can tape more aggressively if you must.  Playing of course depends on the nature of the injury (ex. ACL versus MCL) and what stage of healing you are at. Make sure you warm up extremely well and single leg hops in different directions to not only prepare the ankle and knee but also test it to see if you are ready to go.  Get to game speed movements with and without the ball and see how you feel.  If you can’t operate at full speed without pain or fear then you are better off in the long run not playing yet unless it is a huge game and you are the star.  You want to represent your best self not only on the day, but a month from now too. Be smart and put your ego aside.

• Muscle strains

Extremely similar concepts as sprains.  Joint sprains are usually ok to move on at a certain point but entering tackles or getting tackled poses a risk. With muscle stuff you can experience a set back at any moment just with movement alone.  With a muscle strain if you cannot move at 100%  speed without pain or fear that you will re-injure it, you are better off sitting it out. Be sure to warm up and see how you feel, but if it hurts and seems to be getting worse with time or increase in speed, stop.  Muscle injuries get worse and worse with exposure to pain.  Back off and you will be happy you did in the long run.  Hamstring pulls are the worst, and being composed of primarily fast twitch muscle they will re-injure easily.  Smaller muscles are safer to play with pain than longer ones but enter at your own risk.