That's the point. Green knows how to get open, run off screens, cut to the paint. But him doing so comes at the expense of other players. Green cutting limits Parker's driving lanes. Him running off screens takes the bigs away from their sweet spots and away from other guys needing screens. The other players have to want Green to be a higher option for those things to work. That's why Green would need to get plays called for him.
Essentially, the starting offense is in Parker mode by default. Green mode is something the team can do, but they only break it out on rare occasions. When the offense is in Parker mode, Green does little more than slide around the perimeter. He can definitely slide better than he did today, but he almost always gets open as a result of the defense helping on Parker's drives. No one was stopping Parker from driving in the first and fourth quarters, mainly because they didn't leave Green. If Pop wanted Green to score more, he would have called plays for him like he did in the last Memphis game. Pop will do this later in the series if he feels Green is losing too much focus.
Can you honestly say Green shooting contested jumpers is something the Spurs should ever want when the Big Three are each having above-average performances? I can't. But I'm not worried about Danny's offense. This is a Green series. He will leave a mark on subsequent games.