If this is not caused by the factors influencing injuries that are mentioned in other threads, you'll just have to wait for the injuries streak to stop on its own. I had the same situation last season but now it just vanished. Except for one injury that one of my players got half an hour ago during a normal intensity cardio (I was tempted to do some training because all my players' form was 99%).
All in all, multiple injuries made me more creative with the tactics, having limited player resources