It never changed as a junior in high school when his father was killed at the car wash he owned in Compton, Calif. He just kept right on playing.
''He just internalized it to me,'' said Tony Masi, the athletic director at Martin Luther King High School in Riverside, where Leonard was a prep star. ''We didn't hang out every day. I'd see him for a couple minutes a day. Just watch him and observe him. He didn't show much. He was just shy and reserved.''
It never changed earlier this month when the third-year swingman for the San Antonio Spurs was saddled with the responsibility of defending Kevin Durant, the most talented scorer in the league. He just kept right on playing.
''He is just growing by leaps and bounds so I wanted him to be out there every minute with Kevin tonight just so he can learn what it's like to guard a great player and that is what he is going to be doing his whole career in this league,'' Spurs coach Gregg Popovich said after the game when Durant needed 26 shots to score his 28 points. ''It was a great night for him.''
And it never changed after a game in Minnesota last week when he was asked about Popovich's proclamation that Leonard would one day take over for Tim Duncan as the face of the most consistently successful franchise in the league. He just keeps on playing.
''I've been working hard to be one of the focal points in the NBA, one of the top guys. For him to say that and see that I could be the face, it just brings joy to me,'' Leonard said with an undertaker's enthusiasm. ''I'm just happy that someone else sees it other than myself.''
Right there in that moment, without an ounce of arrogance or pretense, it becomes crystal clear that Leonard doesn't see himself as the next Spurs role player to flourish around Duncan, Tony Parker and Manu Ginobili. He doesn't see himself as the next Bruce Bowen or the next Stephen Jackson or even the next Sean Elliott.
Leonard fully expects to one day join George Gervin, David Robinson and the celebrated trio of Duncan, Parker and Ginobili on the list of Spurs headliners.
''Once the Big Three is gone, you'll probably see a lot more of me taking over,'' Leonard said. ''But right now it's just hard with the top three guys still here.''
Leonard averaged career highs in points (12.8), rebounds (6.2) and 3-point shooting (.379) this season, but the numbers that really stand out are in the most important category: When Leonard is on the floor this season, the Spurs were 54-14.
''He has a great capacity to absorb things and he works hard,'' Popovich said. ''He comes early to practice. He stays after. Our development guys work with him constantly and he wears them out. So he really wants to be good and he's got some talents to work with, so that's a good combination.''
His ascendance is one of the biggest reasons the ageless Spurs just keep on rolling. After a devastating loss to Miami in seven games in the NBA Finals last season, the big question was whether the heartbroken Spurs would recover and mount another run. Duncan is coming up on 38, Ginobili will be 37 in July and Parker will turn 32 in May.
But the 22-year-old Leonard, acquired from Indiana in a draft-night trade for valued veteran George Hill in 2011, has infused this team with young legs, given them a defensive dynamo on the perimeter and another maniacal competitor who gets bored with the cupcakes at the bottom of the standings while salivating over a night matched up against Durant, LeBron James and the rest of the best.
''I feel like those are the best games rather than playing one of the under 50-(win) teams and not really learning a lot because they make a lot of mistakes,'' Leonard said.
Duncan, Parker and Ginobili have won three championships together, seen it all and done it all, and have had a huge influence on Leonard's development.
''When San Antonio grabbed him, I was like thank God,'' Masi said. ''Because he's got Duncan and Popovich and all these guys who won't let him just fade away. He's not in the middle of nowhere. He's got a group that's smart and they're going to show him the way and I think they have.''
Now Leonard is returning the favor, practically without saying a word. The Spurs are starting to adopt his unflappable demeanor.
''Kawhi is steady and as a group we are, but he helps turn us like that,'' Ginobili said. ''We were not like this four years ago. And he provided that type of play.''
Leonard isn't The Man in San Antonio yet. But he will be. Popovich knows it. The Big Three know it. And Kawhi Leonard knows it. He's watched and he's learned and through it all, he's just kept playing.
''They've got a lot of knowledge in the game, just from being around and winning championships,'' Leonard said of Duncan, Parker and Ginobili. ''I think it does help. It shows you how to win if you're on a winning team.
''Once those guys are gone, I'm going to have to start it all over again because I'm not going to have them on the floor. I've got to learn how to create shots for others. And then just having the energy for myself to come out there with a mindset to create shots for myself the whole game.''
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