It's 100% heart and focus, or lack thereof.

You guys blaming Spo are truly blind. If the dude was out there hustling, diving for balls, bullying his way down low, holding his head high, high-fiving teammates, cheering, RUNNING, and taking no prisoners, then he'd get more minutes. He gets benched because Spoelstra doesn't see what he wants to see out of him.

He's physically slow with his footwork, so the only way to make up for that is to hustle and, as tony would say, "do your homework early." He hasn't been doing that lately, and he's getting picked apart. I don't see killer instinct. I don't see work ethic. I don't see someone who can take the bullshit refereeing he gets subjected to with maturity and poise (and I agree that refs really hate him, and it's because he picked a fight and tackled Alex Len years ago).

Dude still has monster potential but right now it just reeks of immaturity and letting negativity get to him. It's completely mental.