Al Horford high-fiving Stephen Curry and Moses Moody as he checked in for his Golden State Warriors preseason debut, was a strange sight for Boston Celtics fans. Depending on who you ask, some would even say disgusting.
If Marcus Smart had played in this game we all might’ve had to find a way to have it removed from the internet https://t.co/qQjwuWGtEE
— Sam LaFrance (@SamLaFranceNBA) October 6, 2025
After seven seasons in Boston across two stints, the big man’s transition out to The Bay Area happened so fast -- kind of.
Though there were reports of mutual interest between Horford and the Warriors all summer, his multi-year deal wasn’t finalized until last week because of the team’s contract disputes with restricted free agent Jonathan Kuminga.
Before Celtics fans could even make their way through the five stages of grief, Horford was already on the Chase Center floor wearing No. 20 for the blue and gold. Though this is an experience the fanbase went through in 2019, when he left town to join the Philadelphia 76ers, I don’t think many expected to see the 39-year-old leave again.
Nonetheless, it’s always jarring to see a beloved former Celtic wearing another team’s colors, even if it’s not for a “rival” as some fans consider Golden State to be (I’m not really in that camp, but to each their own, I guess).
Earlier in the team’s history, there were many greats who only played in Boston. Players like Bob Cousy, Bill Russell, John Havlicek, Larry Bird, and Kevin McHale made it through their NBA careers without taking the floor for another team.
As the years have passed (and a few times earlier on), there have been plenty of beloved Celtics who have gone on to play elsewhere.
It's weird to think about every time.
Dave Cowens, Milwaukee Bucks
After 10 seasons, two NBA Championships, and an MVP with the Cs, Dave Cowens retired from basketball -- until he didn’t. Big Red spent two years away from the game to be Regis College’s athletic director before returning for one final season with the Milwaukee Bucks in 1982-83.
Yup, that's him in the picture wearing No. 36.
Cowens’ Milwaukee tenure isn’t well-renowned, and it’s for good reason.
The eight-time All-Star suited up in just 40 games for the Bucks, starting in 34. He averaged 8.1 points, 6.9 rebounds, and 2.1 assists in 25.4 minutes per game.
Seeing Bucks Dave Cowens was probably a lot like seeing Tampa Bay Bucs Tom Brady, just without the championship-level success. Very odd after a strong career in lovely Massachusetts.
Robert Parish, Charlotte Hornets, Chicago Bulls
Robert Parish has played more games than any other player in NBA history. The lion’s share of those appearances came with Boston, but The Chief spent his final (and early) seasons elsewhere.
Parish elected to join the Charlotte Hornets in the summer of 1994, after feeling like he was no longer wanted/needed by the Celtics.
He ended up making 155 total appearances with Charlotte, but wasn’t nearly as impactful as he’d been in Boston, even in his later seasons. Parish averaged just 4.4 points and 4.2 rebounds per game over two years with the Hornets.
The big man finished his career with the Chicago Bulls, winning his fourth NBA title in the 1996-97 season. Having not been alive to see it, I’d have to guess this was pretty similar to Celtics' Blake Griffin. Not many appearances or minutes, but probably was impactful in other ways.
Paul Pierce & Kevin Garnett, Brooklyn Nets
Paul Pierce and Kevin Garnett are the faces of the Celtics for a generation of fans. Alongside Ray Allen, they helped reestablish the franchise as one of the league’s giants, ending a 22-year title drought in 2008.
In 2013, both men had seen their final days in Boston. Pierce, after 13 seasons, and Garnett, after six, were traded to the Brooklyn Nets for a package that eventually netted the Cs Jaylen Brown and Jayson Tatum.
At 36 and 37 years old, respectively, each player’s best years were behind him. Pierce averaged just 13.5 points per game, while Garnett only posted an average of 6.5.
After just one season in Brooklyn, Pierce wound up joining the Washington Wizards (where he was sneaky awesome, by the way), while KG was traded back to the Minnesota Timberwolves, where he spent the majority of his career, at the 2015 trade deadline.
Rajon Rondo, Los Angeles Lakers (and a billion other teams)
As the only player on this list whose jersey isn’t retired by the Celtics, Rajon Rondo sticks out a bit. He also might be the one whose name stings the most to see. Despite not being immortalized as one of the franchise's greats, he was still a massive contributor on a championship team, who once seemed primed to lead an era of Celtics basketball.
Those hopes came to a conclusive end in December of 2014, when he was traded to the Dallas Mavericks. From this point on, Rondo became an NBA journeyman. He played for eight teams after leaving Boston, most notably the rival Los Angeles Lakers.
Of course, Rondo became one of the few players to win a championship with both of the league’s most storied franchises when he, LeBron James, and the Lakers won the 2020 title down in Orlando in the NBA bubble.
Now, I’m sure someone is reading this who’s appalled that Horford could be mentioned in the same breath as the above legends. At the same time, some people believe his No. 42 should hang alongside their respective jersey numbers in the TD Garden rafters.
There’s no disputing that watching Horford play alongside Curry and Draymond Green is going to take some getting used to.
Buckle up.