i am still willing to try and help you.
make sure they have a rest before and after games.
lower the intensity of the training until the players are back to full fitness
could be something to do with training facilities?
have you applied any extra training to players e.g. positional, or a specific stat? if so lower the intensity or remove it
your players may have low stamina, high workrate, or low natural fitness, or you could be playing them in a position in which they use up a lot of their stamina e.g box to box midfielder
make sure they have a rest before and after games.
lower the intensity of the training until the players are back to full fitness
could be something to do with training facilities?
have you applied any extra training to players e.g. positional, or a specific stat? if so lower the intensity or remove it
your players may have low stamina, high workrate, or low natural fitness, or you could be playing them in a position in which they use up a lot of their stamina e.g box to box midfielder