There are a few reasons can cause injuries. Such as a result of intense training and competitive championships.

You can reduce the risk of your players suffering an injury, but you will never be able to completely avoid them. Here are some examples for things that you can do in order to lower the risk of an injury:

1 Avoid too much training and too many Friendly Matches

2 Avoid your players having a too aggressive Tackling Style

3 Make sure your players have full condition levels before the match. The lower the condition they have, the easier they suffer an injury

Kindly remind that injuries are part of any football match as well as IRL.