SPOILER ALERT: This article contains spoilers for “Who the F**k is Jack McKinney?,” the March 27 episode of “Winning Time: The Rise of the Lakers Dynasty,” which is now streaming on HBO Max.

Like every other episode of HBO’s “Winning Time: The Rise of the Lakers Dynasty,” Sunday’s episode picks up with the Los Angeles Lakers organization pinned against a wall, this time scrummaging for a new head coach after the abrupt resignation of Jerry West (Jason Clarke). With a Palm Springs pre-season training camp on the horizon, the Lakers land on a man who might have more ideas than they’ve bargained for, leading owner Jerry Buss (John C. Reilly) to bellow over the phone, “Who the fuck is Jack McKinney?”

Tracy Letts had the same question when he was asked to play the Lakers coach on the series. Although the actor, playwright and Chicago theater mainstay is old enough to remember the Showtime Lakers’ dominance in the 1980s, he wasn’t aware of the man who innovated the team’s style of play before joining “Winning Time.”

“I certainly was familiar with the Showtime Lakers and I remember the Larry Bird-Magic Johnson rivalry very well,” Letts tells Variety. “But Jack McKinney I did not remember at all, if I ever knew who he was. It was only when they reached out to me to gauge my interest in doing the show that I learned who he was.”

When McKinney takes over training camp, he skips no precautions in instituting his personal basketball philosophy, immediately beginning practice upon his arrival in Palm Springs and closing practice to organization leaders. McKinney believes in fast break offense — a strategy that entails pushing the ball as quickly as possible across the floor after regaining possession. “From now on, we won’t wait for anyone to give us breaks. We’ll make our own. Constant motion offense,” he explains. McKinney’s approach quickly causes friction among the Lakers players, many of whom remain territorial about their roles on the team.

Here, Letts talks with Variety about his interpretation of McKinney’s devotion to his own basketball philosophy, how he sees the character as an outsider within the Lakers organization and the difficult path ahead for McKinney in the season’s coming episodes.

Do you follow the NBA? Are you a basketball fan?

I follow football, I follow baseball. I’m a little more fair weather about basketball. If my teams are doing well, I will watch more carefully.

Who do you root for then?

Because of my Chicago connection, I was only a Bulls fan. I never understood how anybody could cheer for more than one team. And then Oklahoma City got a team. I’m from Oklahoma, and we’ve never had a professional sports team. I didn’t feel like I could just shift allegiances, so I just added the team.

This week’s episode follows McKinney’s introduction into the Los Angeles Lakers, where he is confronted with resistance from both players and organization leaders over his emphasis on fast-break offense. How does McKinney approach that opposition?

What I admired about the writing of [McKinney] was the idea that he’s pretty single-minded in his pursuit. One of the things the show does so beautifully is it really delineates, very explicitly, what all the individual characters have invested in this. For [showrunner] Max Borenstein, [he was] very open about saying, “We’ve done substantial research on this.” But beyond that, it’s a creative imagining. I don’t want to say “he created fast- break offense,” but he certainly is one of the major figures in popularizing it and bringing it into this team. And so [we made] him very single-minded in his pursuit of that [thinking] it would not only be a fulfillment of [his] life as a coach, but it will also bring excitement and interest to this game. Once you boil things down to essential elements like that, it doesn’t matter if you’re talking about basketball. He could be a scientist who’s discovered a cure for something.

How would you say McKinney thinks of himself compared to other leaders in the Lakers organization?

There’s something energetically a little different about him than some of the other characters, even in the coaching realm. He seems very different than the character of Jerry West in the show, very different than Jerry Buss, very different than Paul Westhead or Pat Riley. I love those distinctions in character. They had completed the pilot and shut down for the pandemic. So they sent it and the pilot was so great, fun and energetic. Who doesn’t want to be a part of something like that? But then they also sent me the scripts and they were done. They were not only done, they were polished. For me, that was part of the appeal. It was kind of all there in front of me on the page already.

That sounds like a really pleasant working experience.

Well, the show was very challenging to shoot [through COVID], in this modern TV age, where we want our television to look like movies, but we still want to shoot eight pages a day on a TV schedule. On top of that, we’re going to stage NBA games. How the hell are you ever going to pull this off? But we always had the scripts to go back to. I don’t remember a day when the actors didn’t turn to one another at one point or another and say, “What a great gig.” It had such a clarity of vision and purpose. That’s such a gift as an actor to know exactly what I need to do to help tell the story.

For those who know the story of the Showtime Lakers, there’s a reason why McKinney is taken away from the steering wheel during the season. Looking ahead, does McKinney have a sense of possessiveness regarding his basketball philosophy? How does he feel about his system being instituted without his input?

He feels incredibly possessive. The real McKinney had been asked how he thought about the turn of fate [and] if he was bitter about the way things had turned out. McKinney’s response was “No, because I’ve had love in my life.” That’s the kind of philosophy you have to evolve into. [But] now, he’s a guy who is single-minded in his pursuit. That was one of the great things to play opposite [of] Jason Segel and Adrien Brody. Oh man, just give me more of that.

This interview has been edited and condensed for clarity.

“Winning Time: The Rise of the Lakers Dynasty” airs Sunday at 9 p.m. on HBO.