Substitutes
As well as naming a starting eleven players for each fixture, the manager has to name four substitutes. One of the four substitutes named must be a goalkeeper while the other three players can be from any outfield position.
The use of substitutes will be determined as a game is played based on the state of the game. Players performing badly, carrying injuries or in risk of a sending-off may be replaced if required.
If the result is looking negative then a more attacking formation may be selected by use of a substitution. Transversely, a more defensive look may be adopted if a team is hanging on for a positive result.
Goalkeepers will only be used if the starting keeper is injured, sent-off or performing extremely poorly.
Substitutes will usually receive lower than normal performance ratings in line with the time they spend on the pitch. On the occasions when a substitute does get rewarded with a high rating it is worth considering that the player may be ready for a starting place pretty soon, especially if you have players regularly not performing.