BOSTON — All of the attention on the Mavericks’ blown Game 4 victory was, rightly, focused on Luka Doncic, but there was also an unsung hero, Derek Lively II, who dominated the paint and was crucial to Dallas’ chances of pulling off a miracle.
And Lively has his own unsung hero: Mavericks’ top assistant Sean Sweeney.
“Without Sweene, I wouldn’t be here,” Lively, an All-Rookie selection, said, using his coach’s nickname. “Our workouts started three days after I got drafted. I couldn’t do a left hook. So, from where I started to where I am now, without Sweene, I wouldn’t be here. Pushing me, encouraging me, watching assist film, understanding how to read the game. He’s always like a little devil on your shoulder telling you to try harder. He’s a great guy to have your back.”
Within the Mavericks, Sweeney is known as a tireless worker and defensive coordinator, who rose to seventh in the rankings after joining the team in 2021, up from 21st the year before.
League-wide, he is considered one of the top assistant coaches and, at 40 years old as of this month, is on his way to becoming a head coach.
Jason Kidd knows what’s coming.
“He’ll be the head coach soon,” Kidd told The Post.
Sweeney began his NBA career as the Nets’ video coordinator, working with Kidd during the 2013-14 season.
They’ve spent the better part of the past decade together, with Kidd employing Sweeney during his stints with Milwaukee and now Dallas.
“It’s a great partnership,” Kidd said.
Along the way, Sweeney, who previously interviewed for head coaching jobs with the Hornets and Jazz, built quite a network.
During his time in Brooklyn, he earned the respect of Kevin Garnett, who colorfully told teammates during a film shoot to shut up and listen to the young man because “he knows what he’s talking about,” according to the Dallas Morning News.
In Milwaukee, he personally coached Giannis Antetokounmpo over the summer and toured Greece, Andorra, Croatia and other countries with the MVP.
Last week in Boston, Sweeney was spotted meeting with Bill Belichick in a hallway.
And for this summer’s Olympics, Sweeney will join the staff of Luka Doncic’s Slovenian national team after discussions with Doncic’s father, Sasa, and federation officials.
“He does all the strategy. He scouts the defense. … He talks to us,” Doncic said. “He’s been great for this team since the day he got here.”
In terms of player development, Sweeney’s most recent success was Lively, who was the big hit after being drafted 12th overall.
The 7-foot-1 Lively may have found something to exploit in Game 4, when Boston had no answer for his dominance in the paint.
The 20-year-old grabbed 12 rebounds, including seven offensive rebounds, in just 22 minutes.
With him on the court, the Mavericks outscored Boston by 20 points.
The Celtics could counter with Kristaps Porzingis, but the Latvian’s availability for Game 5 is unclear due to a foot injury.
So when the Mavericks outrebounded the Celtics 52-31 in Game 4, it opened the door for Sweeney’s Mavericks to mount an incredible comeback.
And even if that doesn’t happen, the consensus is that they have one of the best assistants in the league.
“He’s a guy that pays attention to detail, and he’s perfect at everything he does,” Dallas forward Josh Green said. “Defensively, he’s in command of us. He’s a very smart coach, he’s great at making adjustments. He’s a game nerd, and it’s great to have him around because as a young guy just coming into this league, I was always putting in the effort. And then I’d come back in the gym late at night and I’d see him all the time. It was impressive and very encouraging to see him every night.”
