Hamstrings are from over-exertion rather than collision (like your one broken bone), so therefore they are probably incurred from low fitness or a heavy pitch/weather conditions. Also, are your injuries incurred in training? If they are, it's likely your player is doing too much.
If you're in the lower leagues (I know the Championship isn't exactly lower league), i've found that pitch condition can make a **** of a difference. I had a save with Weston on FM12 and my pitch condition was 'terrible'. As a result, I was getting 1 or 2 injuries a game in pre-season! Not ideal.
Like ajt08 says, persevere and it'll pay off. Until then, have a tinker with training schedules and ask your board for better facilities and/or a better pitch (if you need it obvs!)