BOSTON — As the focus on the Mavericks’ Game 4 dominance understandably went to Luka Doncic, there was an unsung hero, Dereck Lively II, who owned the paint and remains important to any chance of Dallas pulling off a miracle.
And Lively has his own unsung hero, Mavericks top assistant Sean Sweeney.
“I wouldn’t be here without Sweene,” Lively, an all-rookie selection, said, using the nickname for his coach. “Our workouts go back to three days after I was drafted. I couldn’t make a left-hand hook. So just knowing that where I started to where I am now — I wouldn’t be here without Sweene. Pushing me, encouraging me, watching assisted film and understanding how to read the game. He’s always going to be that little devil on the shoulder telling you to go harder. That’s an amazing person to have your back.”
Inside the Mavericks, Sweeney is known as a relentless worker and coordinator of a defense that rated as high as No. 7 the season after his arrival in 2021 — up from No. 21 the year prior.
Around the league, he’s considered among the top assistants and, at 40 years old as of this month, on a head-coaching trajectory.
Jason Kidd understands what’s coming.
“He’ll be a head coach soon,” Kidd told The Post.
Sweeney’s NBA career started as a video coordinator with the Nets, where he linked up with Kidd during the 2013-14 campaign.
They’ve been together for most of the past decade, with Kidd hiring Sweeney for his stints in Milwaukee and now Dallas.
“It’s a great partnership,” Kidd said.
In the process, Sweeney, who previously interviewed with the Hornets and Jazz for their head-coaching positions, accumulated quite a Rolodex.
While with Brooklyn, he notably earned the respect of Kevin Garnett, who colorfully told his teammates during a film session to shut up and listen to the youngster because “he knows what he’s talking about,” according to the Dallas Morning News.
In Milwaukee, he personally trained Giannis Antetokounmpo in the summers, traveling with the MVP to Greece, Andorra and Croatia, among other places.
In Boston last week, Sweeney was spotted meeting in the hallways with Bill Belichick.
And this summer at the Olympics, Sweeney is joining the staff of Luka Doncic’s Slovenian team after conversations with Doncic’s father, Sasa, among others involved with the federation.
“He does all the schemes. He does the scouting for defense. … He talks to us,” Doncic said. “Since the day he came here, he’s been a great addition to this team.”
As far as player development, Sweeney’s latest triumph is Lively, who was picked 12th overall and became the steal of the draft.
Lively, at a towering 7-foot-1, may have found something to exploit against Boston, which had no answer for his paint dominance in Game 4.
The 20-year-old was a force with 12 rebounds — including seven offensive — in just 22 minutes.
The Mavericks outscored Boston by 20 points with him on the court.
The Celtics could counter with Kristaps Porzingis, but the Latvian’s status remains unknown for Game 5 because of a leg injury.
So as the Mavericks out-rebounded the Celtics in Game 4, 52-31, a potential avenue opened for Sweeney’s Mavericks to pull off an unthinkable comeback.
And even if that doesn’t happen, the consensus is they have one of the league’s best assistants.
“He’s a huge X’s and O’s guy. And he’s on top of everything he does,” Dallas forward Josh Green said. “Defensively, he’s on us. He’s a very smart coach and good with adjustments. He’s a nerd for the game and it’s awesome to be around that because being a young guy coming into this league, I was always leaning on putting work in. And I would see him whenever I came back late at night to the gym. And seeing him every single night, it was impressive and very encouraging.”
