Blitz: The League II

For this achievement, you have cause the gruesome injury of the ruptured scrotum ten times. (Not the most pleasant thing to see in the injury cut scene!)
First you will need to build up some clash meter by gaining yardage and scoring touchdowns etc. After earning a full clash meter I would start trying to do as many dirty hits as possible when in defence aiming for the crotch or stomach region. A few hits to the crotch region and a worn down stamina rating will help get this achievement on its way. Whilst wearing down the stamina of a player, I would recommend all big hits on the same person if possible, you will be able to execute your first injury to the crotch/stomach region. Usually this will be a bruised kidney removing them from match for several plays. When they return focus on getting clash icons by executing "Beat downs" and other such moves. When enough icons have been collected you will gain "Unleashed" then you will need to aim all of your unleashed force on the poor victim you have been wearing down and caused the kidney injury on. A nice big hit to the crotch and pop goes the testicles. Repeat a further 9 times for the achievement. I would suggest playing in "Bone Breaker" mode as the bigger injuries come much easier as damage is increased. Also an easy way to find your victim is to start at kick off with a standard kick off, but aim to the extreme right and only press two of the correct buttons so you end up with around 40% power. This will cause the kick off to go the same person every time and will give you a clear run up on them to aim your tackles easier.
Hope this helps, any more questions or things you think that i should add feel free to comment. :)

Credit to Doominatorx6: Aim for the front of the player as tackles from behind generally result in back injuries such as bruised kidney or ruptured spleen.

This achievement is based on getting one injury 10 times.

What you must do over the course of playing the game (not just one career) is get 10 ruptured scrotums. To do this you must be get the "unleashed" ability then hit the ball carrier. To get "unleashed" all you have to do is do specific things during the course of the game to fill up your clash meter icons. When it allows you to select a specific body part go for the groin or midsection and pound A as fast as possible. After 10 times the achievement unlocks.