Some people here have mentioned this before, how Pop has taken the "Tony Parker" approach with Green, where he's very hard on him, stopping just short of Adrian Peterson tactics..
It may be a reason for the limitation on Green's minutes when he's struggling, too, it's the only logical explanation IMO(you could argue that he sat him for Belinelli early on for offensive purposes, but realistically, Green is just as good as him on offense in the Spurs system, if not better, tbh)..
Pop's approach seems to be working, as Green has had 2 of the greatest playoff shooting runs in NBA history since his disappearing act in 2012..