u should only take a day off if its leg day for u.
about the knee:
cardio itself is really intense since its about going hard from start till end & even after getting used to it, u should still make sure to be really tired after the cardio..
so doing soccer the same day INTENSELY for an hour first time after 2 years was probably not a smart move.
the thing about soccer is that while running with the ball, your legs are being used WRONG. think about how u use your legs when running regularly. toes pointing forward, heal in the ground first, then the outer side of your feet ending with your big toe on the ground in the end..
then compare it to soccer! soccer kills your knees & hips, probably your ankles too mate :
just dont do that much soccer at once, or at least try to skip cardio on those days & separate soccer (probably cardio too, but that depends how u feel about it) from your leg day. if u work out legs for example monday & do your whole body in a week. then dont do soccer sunday & tuesday. after getting used to it, maybe play soccer on tuesdays anyway, but do NOT let it ruin your leg workouts by killing your legs the day before leg workout.
if your knee keeps bothering u, then do 2weeks of light-weight lifting & if that doesnt help, youre screwed so go see a doctor
though im sure its just a sign of over use & wont result in injury. we all need to test yourselves in overtraining ways when it comes to sport now & then. i know how it is
good luck!
