I think waiting until Thursday is adequate rest time.
My comments on Mazzone’s comments…
(1) Note that he has a distinction between “pitching” and “throwing”. Mazzone is big on throwing in between pitching outings. I think lots of people today agree with that thinking (lighter throwing the day before or after a pitching outing, heavier other days). But letting pitchers go as long as they can is risky business - especially with young kids. Technically, it depends on how you define “as long as he can”. But it also takes a knowledgeable coach with a keen eye to detect when a pitcher has reached that point (probably by noticing a deterioration in the pitcher’s mechanics). It’s not worth the risk to kids’ arms.
(2) Mazzone’s comments sound like they are geared to adults. Young kids with their immature skeletal systems are more vulnerable injuries (e.g. growth plate injuries). Plus, many of today’s kids play on multiple teams/leagues, play in travel ball tournaments where it is not uncommon to play 6 games over a 2-day weekend, etc. The pros don’t do anything like this. Make sure you understand the context in which Mazzone’s comments apply.