Player loyalty is the level of a player's being loyal to their club in FIFA Ultimate Team. With loyalty, a player gets one bonus chemistry point, which helps you make the most of their stats on the pitch. Loyalty is indicated by the green shield icon on players card, when the loyalty shield is greyed out, it means there is no loyalty.
Players found in packs automatically get full loyalty, but those acquired in the Transfer Market do not. Players can get loyalty when they play for your FUT club minimum 10 games.
Player loyalty was announced in FIFA 14 Ultimate Team for the first time as a new feature to make Chemistry system better and more accurate.