The Boston Celtics’ trade for Kevin Garnett in the summer of 2007 had a seismic impact. Overnight, the Celtics were transformed from one of the Eastern Conference’s worst teams into a contender.
As the Celtics marched to 66 regular-season wins in Garnett’s first season in Beantown — a 42-win improvement from the previous season — Matt MacKenzie was one of the many fans in New England locked in on their journey. Then a sophomore on the Husson University men’s basketball team in Bangor, Maine, MacKenzie often had friends over to watch games in his basement. Twice that season, MacKenzie ripped off the 3 1/2-hour drive south on Interstate 95 to Boston to catch games in person.
“Seeing that trade happen with K.G. coming to the Celtics, that was everything,” MacKenzie said. “He changed the entire culture of the Celtics organization.”
After college, MacKenzie wasn’t ready to be done with basketball. He started working with children as a skills trainer in his home state of Maine. One of his clients was Cooper Flagg, whose ascent in the basketball world over the past five-plus years has been stratospheric. Flagg has gone from being a top-rated high school prospect to one of the brightest young stars in the NBA. The Dallas Mavericks rookie has already set the league scoring record for a teenager twice and flashed so much promise on both ends of the floor that it’s easy to envision First Team All-NBA appearances in his future.
On Friday, Dallas will play in Boston for the only time this season. It has the potential to be an electric atmosphere. The Mavericks-Celtics matchup in T.D. Garden will effectively serve as a homecoming game for Flagg, whose inner circle grew up bleeding Celtics green before the Mavericks chose Flagg with the No. 1 pick in June and altered their allegiances.
“Everybody I’ve talked to has had this date circled since the schedule released,” said MacKenzie, as Flagg returned to the floor Thursday against the Orlando Magic after missing the previous eight games with a left foot sprain. “I would not be surprised if 75 percent of T.D. Garden or more reside in Maine. I know several people have boxes and suites reserved. I know a ton of people who scraped together their money just to get a seat in the balcony.”
Cooper Flagg has been a force on the court for years. He was able to showcase his abilities playing with Maine United in 2023 on the Nike EYBL circuit. (Stu Boyd II / The Commercial Appeal via Imagn Images)
The Maine United AAU basketball team that Andy Bedard coached had an old-school ethos. He taught his players to pass the ball, rebound, play defense and set solid screens.
Loyalty also mattered.
“There was no way (Kevin) McHale was going to go to the Lakers,” Bedard said. “There was no way (Larry) Bird was going to play with Magic (Johnson). It was just like this is your group. You’re tough. You play together. And you compete at all costs. That was how we played.”
Bedard, who played collegiately at Boston College and the University of Maine, grew up on the 1980s Celtics, who made five trips to the NBA Finals and won three championships in a seven-year span. Bedard’s lasting memories from that era of Celtics basketball are of Bird going airborne to try and wrangle loose balls.
“My head goes to Bird laying out on the floor,” Bedard said. “Diving on the floor into the stands. The all-out laying it on the line, where you sacrifice everything for the possession.”
Bedard’s son, Kaden, played on Maine United with the Flagg brothers, twins Cooper and Ace. Bedard knew the Flagg boys’ mother, Kelly, from college. She was an accomplished four-year player at the University of Maine who, as a senior, helped the Black Bears upset Stanford in the first round of the NCAA Tournament in 1999.
Kelly Flagg was also a massive Celtics fan. When her boys were in grade school, she bought them a DVD of games from the Celtics’ 1985-86 championship run. The boys watched it while mom wheeled the family minivan through Maine on the way to practices or games.
“I think if you grew up and you were an Allen Iverson fan, you were probably more of a one-on-one type player,” Bedard said. “But if you watched that team, the ball moved. You set real screens. You slipped screens. You got the ball to the mismatch. The way they played, I think it embodies Cooper exactly.”
While Flagg is capable of erupting for 49 points — like he did Jan. 29 against the Charlotte Hornets and his former Duke teammate Kon Knueppel — his ability to impact all aspects of a game is what stands out. Flagg ranks first on the Mavericks in rebounds and assists, second in steals and third blocks. In transition, he’s often the team’s first player racing ahead for an easy basket or sprinting back on defense to try to disrupt a fast break.
“We had no idea Cooper was going to become this 6-foot-10, athletic guard who can play center,” Bedard said. “We knew we had to teach these kids to play fundamentally first. Always make the right play, the right pass, and play the possession the right way. I think that’s just kind of how he plays. Obviously, he got all of the athleticism and the size, too. It just kind of all came together.”
When Flagg and fellow rookie and former Duke teammate Kon Knueppel met on Jan. 29, both had monster games. Flagg had 49 points for the game. (Kevin Jairaj / Imagn Images)
Flagg is locked in a closely contested battle against Knueppel for Rookie of the Year. While Flagg wants to win the award, he is more focused on the bigger picture in Dallas. The 12th-place Mavericks are 21-41 after a 115-114 loss to the Orlando Magic on Thursday. Flagg wants to turn his team into a winner again soon.
“He has championship aspirations,” MacKenzie said. “He sees these teams from the past. You talk about the 2008 Celtics and those (Golden State) Warriors teams. Seeing how those teams competed in the playoffs and what made them so successful, they weren’t just led by one player.”
The 2008 Celtics included Paul Pierce, Ray Allen and Garnett, plus Rajon Rondo at point guard. The Warriors, who won four championships between 2015 and 2022, starred Stephen Curry, Draymond Green and Klay Thompson, Flagg’s now-teammate in Dallas.
The Mavericks will get Kyrie Irving back from injury next season, but there is still work to do in order to put other winning pieces next to Flagg. The Mavericks are hopeful they can land an impact player in this year’s draft.
As Dallas tries to build around Flagg, Boston is competing for another championship. Jayson Tatum has yet to play this season recovering from a torn Achilles, but on Thursday, he was upgraded to questionable to make his season debut Friday night.
The Celtics are 41-21 without Tatum, their six-time All-Star, because Jaylen Brown (28.9 points per game) has emerged as an MVP candidate, and role players around him have made major strides. Reigning Sixth Man of the Year Payton Pritchard has given the Celtics excellent production in 48 games as a starter, and 26-year-old center Neemias Queta — a former Sacramento Kings second-round pick — is a Most Improved Player candidate.
“They have done a good job with (president) of basketball operations Brad Stevens running the show,” MacKenzie said. “Keeping guys there and having the right people coach the team.”
Flagg will have plenty of supporters inside T.D. Garden on Friday, but Bedard said he doesn’t expect Celtics coach Joe Mazzulla or Brown to take it easy on him.
“I think that Jaylen Brown is going to try to f—ing lock him up and remind people that Cooper is great, but this is my team and my core, and I’m an MVP type player,” Bedard said.
Flagg’s inner circle will be rooting for the Mavericks to win. But they’ll be in the minority among the many Mainers who will make the trek to Boston, Bedard believes.
“I expect most of the state to shut down,” Bedard said. “It will be like the only game the Celts play; there will be a bunch of (No.) 32 Mavs jerseys, for sure. I expect him to get a massive ovation from the Mainers and even the non-Mainers. Massachusetts, the Rhode Islanders, Connecticut … I think everyone has a respect for how Cooper plays and his story. I think they would love to see Cooper have 40 and the Celtics win by one.”