You can use one match booster per match. They are very powerful and can help you impact the match.
 
The "Defense" booster is most powerful being used early in the match and when you are winning. The boost makes your defence stronger in stopping your opponents attacks.
 
The "Midfield" booster is most powerful being used early in the match. The boost gives you more possession and you will create more chances.
 
The "Attack" booster is most powerful being used late in the match and when you are behind. The boost gives you a few extra chances and an increased finishing bonus.