This in the second most time consuming achievement in the game. As it says, play on Legend with 20 minute quarters and extreme injuries turned on. Once again, no simulating, or you end up wasting a lot of time.
A few tips with this, Spoil! A Lot! The AI will always beat you in the air when it comes to a contest. Only go for the mark when you are a few metres ahead of the other player. If there is a contest, + to spoil, then run onto the ball. If you have enough room to kick the ball, do so, otherwise I recommend handballing and tacking until you have the room to kick.
You’ll only need 15+ wins from the season to make it into the finals, so there’s no need to exit the game if you are losing. When you do reach the finals however, if you’re going to lose, Exit and play again.