Montrose Christian School basketball Coach Stu Vetter in the basement of his Vienna home Tuesday with a poster of former Montrose Christian standout Kevin Durant. (Matt Breen/The Washington Post)

As Kevin Durant began the fourth quarter of the opening game of the NBA Finals in Oklahoma City, a memory raced through Stu Vetter’s mind.

It wasn’t about the time Durant led Vetter’s Montrose Christian team to a comeback win over Oak Hill Academy. Or about Durant’s ability to dominate with ease but also know when to defer to teammates. It wasn’t his court vision either. That’s something you just can’t teach, Vetter said.

It was a memory that had little to do with basketball.

“My assistant coach, Dan Prete, would say that Kevin would always ask him ‘Do you have any extra change’ for the Metro,” said Vetter, as he watched Tuesday night’s game in the living room of his Vienna home. “I told Coach Prete that I bet Kevin doesn’t have to ask for that change anymore.”

Durant played his senior season at Montrose under Vetter. To get to the school, Durant rode two different Metro lines each way from his home in Seat Pleasant to the school in Rockville. Class began around 8:30 a.m., but Durant arrived two hours early to shoot around with teammates. The school day and a team study hall were followed by weight-lifting and practice. Durant then would head home around 8:30 at night.

Vetter called Durant a “gym rat” whose dedication was uncommon among players with his talent.

Vetter has coached high school basketball since 1975. He’s been named national high school coach of the year twice. He’s coached future Olympians and NCAA champions, future corporate leaders and television broadcasters. But he has never coached an NBA champion.

He inched a bit closer as Durant’s Thunder edged LeBron James’ Miami Heat, 105-94, in the first game of the best-of-seven series.

“He wants to be the best,” said Vetter. “He wants to win. He wants to win a championship. He wants to be the guy that leads his team.”

Durant was 16 years old when he attended Montrose, one of the area’s perennial baskeball powers. His game was so developed that Vetter said Durant could have played in his high school game on Friday night and suited up for the Wizards on Saturday afternoon. In 2006, the NBA prohibited high school players from entering the draft.

Durant also was unselfish and humble. Vetter said Durant easily could have averaged 35 points per game. Instead he dropped in 20 for a team he led to a record of 25-2.

“He’s a good teammate and a lot of big-time stars aren’t necessarily good teammates,” Vetter said. “He’s genuinely liked. I think if Kevin didn’t play basketball, he’d still be a very popular and likeable guy. That’s not the case with a lot of stars.”

A basketball lifer, Vetter couldn’t simply watch the NBA Finals game from his leather recliner. At times he needed to coach.

In order to limit James, Vetter said the Thunder had to cut off his drives to the hoop. If Durant is guarding him, he’d have to use his long arms and give James a buffer zone, cut off his drives to the hoop and force him into outside shots. When Durant found himself guarded by the shorter Dwyane Wade near the foul line, Vetter called for him to drive. And Durant did, for an easy bucket.

“Is that a pretty shot or what?” Vetter said with a laugh. “The rotation, his left hand guided it over top of the defenders hand and he lays it in.”

With time waning in the fourth quarter, Vetter let himself become a fan. He said he becomes nervous before his former players play important games — the nerves a parent, not a coach, feels, he said. Vetter texted Durant a good luck message Tuesday morning, and the 23-year-old answered back.

“Thanks coach,” Durant wrote, “this is for Montrose.”