In need of a long rest + demands more playing time. help? (FM20)

[Speedyol]

Hi. I have a player who wants to start more matches. But he is constantly "in need of a rest". I want to try and keep the promise. What do you guys do in this situation? If he gets decent ratings and perform, does it matter that he is tired?

Do you think it matters if its league matches or Euro cup matches? I am in the group stages.
Does it matter if he is training or not?
Does amount of training affect how jaded a player is`? I had 14 days without any matches and he had fitness of 74% at the start of the next match.
Is it important that he skips matches too cure jaded state? Does it not count if the whole team has a 14 day between matches?

Finally is there a way to prevent this situation in the first place? if I want to keep him fit, he cannot play Saturday and Wedensday matches 3 weeks in a row, and If I play him only saturdays, he is missing 30-50% of the matches, so he complains.. Does fixture type matter, could I rest him in cup matches and only play him in the league or something? 

Thanks for any advice!