In Championship Manager, just as in real football, it is very important to rotate your team. This means that you can not use the same players in every match for a whole season. You should change the playing squad now and again. This way you can achieve two things.

First, you will let your players rest. If you use the same player for a prolonged period of time continuously, then you will find his condition will drop more easily during matches, and he will recover more slowly. While rotating your squad you give him the time to fully recover from the previous matches/ This is very important if your team is also playing in european competitions, giving 2 matches every week.

An important note is that a player will generally easily recover from a game and go up to 99% fitness, yet he sometimes might stick to it and not move to 100%. Though the difference is small in numbers, it can make a crucial impact on how the player performs. Generally a 99% performance persisting for more than a week will mean that the player will most likely have some problem with the training schedule, he migth be unhappy with something (you?) ot he might be very very exhausted and in terrible need of some time off first team football

Second, rotation will help you keep your whole squad in full form, If you click on a player that does not get match time, you will see that he is "lacking match fitness" Now, if you have to use this player, for example after some injuries in your first-team players, he will perform below his average standards.

There is also a third reason why rotation is important: Simply enough, it helps you better evaluate your squad. It often happens to me that i have underestimated a player and i don't give him playing time for months. Then i put him on the pitch one day, and he surprises me by his appearence. Rotation helps you find those players you had simply "forgotten".

Finally you should not forget that for a player to achieve his full potential, just training is not enough. You should also give him playing time. And rotation lets you give playing time to those youngsters that are not yet good enough to act as first-team regulars but with proper care will become your team's next superstars!

So remember: Always rotate your playing squad. Also when you are reaching the end of a match you are clearly ahead, try make substitutions to give playing time to as many players as possible