Injuries are common things in human life. There is a little risk of injury during work. If there is a minor mistake or negligence, there can be an injury. Similarly, players receive injuries in the playground, they receive injuries. There is a difference between the injuries we receive during the general work & the injuries received in the playgrounds.
If a player comes to the ground fully prepared & carefully, there are fewer chances of injuries for him as compared to other players, but we cannot say that he will not receive injuries at all, every player receives some injuries in his sports life. Common injuries received during playing games can be cured within one or two days, but sometimes a player receives a serious injury, as a result he has to be out of the field for a long time.