OK, I started my BAL last night just for you
What was the question again? Ok, you certainly can train for different positions. There is actually a 'shop' in the mode where you can buy (for 500GP) exp for extra positions. You can train your player in lots of ways.
Actually, found a good video here:
Go to 6'24" for the extra positions reference. Around 5'34" starts the shop menu.
You can start the game either as a created player or a current player.
Anyway, in my first three (training) games I scored one key goal and picked up two yellow cards, 6, 6.5 and 6.5

I'm playing as an AM.
Edit: Oh, and I'm playing on Superstar level.