How Do I Raise Player Chemistry?
You can raise the Player Chemistry figure with one of two bonuses, both adding +1 to the figure (capped at 10): Loyalty and Manager.
The Loyalty bonus (+1 to Player Chemistry) is conferred when a player is used in 10 matches. Players that are found in packs automatically have this bonus.
The Manager bonus (+1 to Player Chemistry) comes when the player and the manager share either the same league or same nationality.