Late in the first quarter against the Houston Rockets, James Harden sizes up Justise Winslow at the top of the arc before initiating a pick-and-roll. As the screen approaches, Winslow presses up on Harden to better position himself. Sensing this, Harden makes the typical Harden play, catching a brief moment of contact, rising up for a shot and drawing the foul.

It’s the sort of call that can derail many rookies. They’ll feel like an established player is getting the benefit of the whistle, and they’ll react. It might be a visceral, emotional reaction. It might lead to gabbing at the officials, or blaming a teammate. More often than not, it leads to further mistakes.

But Winslow? Nothing.

“It didn’t affect him on the next one,” Erik Spoelstra said. “That is unique.

“You’re all over the place usually with young players. You’re trying to manage their emotions and teach them NBA situations. It usually takes months, even years, to learn and recognize NBA situations and then to develop a level of competitiveness that’s necessary at this level. He already has shown strides in those areas.”

The numbers so far are very good. The Miami HEAT have a Defensive Rating of 85.4 with Winslow on the court, and he’s earned the early trust of a coach trying to make the playoffs with a veteran-laden roster. In the last 30 years, only 19 teenagers played more minutes than Winslow (75) through the first three games of their careers.

The numbers so far also don’t mean much at all because we’re only three games into his career. Many of the most useful defensive metrics available aren’t even available yet. What matters is how Winslow looks on the court. He looks like he belongs. And how.

“He gets low and he’s wide,” Chris Bosh says. “He’s got incredible size for his age. His physique, his quickness, everything.

“Watching Duke last year, when Coach K put him at the four, I was like, ‘Oh, I don’t know’. But then you see his size, and he’s huge. He’s fast. He’s just one of those guys that can guard one-through-five.”

Physical attributes are great, but plenty of players come into the league with those and never amount to much at all on the defensive end. At the very least, it usually takes some time for them to figure things out.

What seems to separate Winslow from the pack is his mind, his unwavering stoicism on the defensive end and the fact that he actually cares.

“Whether it was in High-School, with Team USA, Duke, I always just took defense personally,” Winslow said. “There was never one person that showed me how to play defense. I think everyone can play defense, it’s about really wanting to. Some guys are more athletic of course, but you have to lock in and want to do it. Not everyone wants to do that.”

When Shane Battier was in Miami, often taking the toughest defensive assignment on the floor to free up LeBron James for greater offensive responsibilities, he would catch a lot of flack when his charge had a big game against him. He’s too old, the proverbial they would say. He can’t handle that guy. Get him out. Battier never seemed to care. If he got beat because Carmelo Anthony hit a bunch of tough two-point jumpers off the dribble with a hand in his face, so be it. There’s only so much you can do.

Winslow already seems to have that bit of mental chess figured out.

When LeBron James was hitting incredibly tough jumpers on Winslow the other night, with Winslow refusing to get bullied in the post, it didn’t faze him one bit.

“Guys will make tough shots, guys are going to miss open shots or miss hard shots,” Winslow said. “You just got to stay even-keeled.”

And when Winslow was chasing Harden around screens a forcing him into tough, contested misses, he had the exact same reaction.

“LeBron was scoring on me, [Harden] wasn’t really scoring on me, but if you look at my facial expressions on both those guys, it never really changed,” Winslow said. “Same facial expression when LeBron was scoring, the same when James was missing shots.”

“He doesn’t get caught up in the emotions,” Spoelstra says. “He can stay focused on one play. What a player does on one possession doesn’t affect him on the next possession.”

“His composure is unbelievable,” adds Bosh.

While Winslow appears perpetually non-plussed after defensive possessions – he’s not a robot, mind you, as he’s shown plenty of emotion on the offensive end – his approach also appears to affect how he actually looks while D’ing up.

Against Harden, James and others such as Kevin Love, Ty Lawson and Trevor Ariza, he’s rarely bit on up-fakes, opting instead to keep his hands up and feet down.

“They’re fakes, so there’s no point in leaving the ground,” Winslow said. “You just have to stay disciplined. I go for fakes a lot, but it helps when you have a guy like Dwyane [Wade] in practice. You can get used to fakes from there. Just try to stay down and be the second one off the floor.”

And in the middle of possessions, Winslow hasn’t over pursued his marks. Just watch him stifle Harden (with help from teammates), stay in his stance, stand as Harden gathers himself, then get right back into his stance.

There’s something spooky about that. Winslow isn’t on the court playing with manic energy, hopping around and waving his hands like crazy. He’s just there, waiting, expressionless. Score on him? He’s there. Miss your shot? He’s there. Silent, steady and ready, like a horror villain always walking towards his prey. The basketball version of It Follows.

“He looks like that. That’s his mad face, same as his happy face, I guess,” Bosh said.

None of this is to say that Winslow is guaranteed to become one of the league’s best defenders. As a rookie with plenty to learn about help defense and recognizing offensive sets, he’s not even guaranteed to have an overall positive impact this season as far as the numbers will show. The road ahead is long and full of challenge.

That’s how the counter-argument with Winslow goes. He’s a rookie. He’s 19-years old. Only seven teenagers have ever posted a Defensive Box Plus/Minus over 1.0 in their rookie season. Rookies just aren’t supposed to be good on defense.

It’s all valid. It’s also doesn’t have to matter. Maybe Winslow is in that group of elite defenders. Maybe he’s can be one of the first wing defenders to have a positive rookie season. Maybe he won’t be. What matters is that he appears to have the right tools and the right demeanor for the job. That’s as important for next year as it is for tomorrow.

For now, it can just be a good thing that Winslow is on the right path. Because unlike many players who don’t start caring about defense until they get to the professional level, Winslow’s path seems to have begun long ago. And somewhere on that path, Winslow learned one of the most important lessons a defender can learn.

“It didn’t piss me off,” Winslow said about teammates in the past not caring as much about defense as him. “You just have to know, not everyone is built the same. You just have to try and make guys better and bring them along with you.”