The Individual training schedule
Nothing more than set up skill to train for each day of week in advance for every player in the team
Lots of managers change players on training fields even every day. Some of them do this because of boosts for important games, some because of "parallel" training of few skills.
The mesocycle and microcycle training.
If the individual training schedule for one week will be possible to save (microcycle) and at the same time, manager could save e.g. four different microcycles, it will be possible to create long term training plan for player (mesocycle). Saving several different mesocycles will give manager possibility to define e.g. training plans for each position. Number of training combinations should be enough to open plenty of discussion about "perfect" training plans between managers ...
What is important, even training will be set up automaticly, it will still required manager attention due to players training speed or potential blocks in skills which are unpredictable.