the condition of the player doesnt really matters i guess.. except they reach red color.. and its a waste to spend token to change the time of the match... unless your are a buyer of course and even then, its still a waste of money (thats worse)
also, you should be aware of that and check the times 1 day before.. so you will know what is in front of you next day, so keep players rested.. i never had problems with it.. only problem may be if you have another match 5 minutes later... anything more than 5 minutes should not be a problem since i think 10 minutes is enough to prepare your team for the upcoming match and anallyse opponents formation etc.