These days, Danny Ainge is known as the Boston Celtics‘ savvy general manager. His smart trades, draft picks, and team-building philosophy have kept the Celtics relevant for the last 10 years. Yet Ainge’s legacy as a Celtics great is equally built on his time as a player. Part of a legendary Celtics team, he won two NBA Finals, in 1984 and 1986, with Boston.

What often gets overlooked is that Ainge spent the latter half of his career playing for NBA teams in the Western Conference. The key moment came in 1989, when the Celtics traded Ainge to the Sacramento Kings. Let’s look at that fateful trade and its ramifications.

Danny Ainge’s trade to the Kings

The Celtics traded Ainge to the Kings with little warning amidst the 1988-89 season. The trade yielded the Celtics center Joe Kleine, who they hoped might fill the shoes of the legendary Robert Parish, then at the end of his career. Most NBA fans assume that Ainge must’ve felt angry and betrayed to be dealt away so suddenly, after seven and a half years of faithful service in Boston.

Yet on the contrary, Ainge was actually excited about the move. To understand why, you’ll need to take in the context of the Celtics’ team at that time. Stars Larry Bird and Kevin McHale had both been struggling with injuries. Robert Parish was getting old. And talented 1986 draft pick Len Bias had recently died as the result of a drug overdose.

The writing on the wall was clear: the Celtics were at the end of an era. And Ainge for one didn’t want to stick around to be a part of a long and painful rebuilding process. As Ainge himself put it, according to The Boston Globe, “I just felt our team after the ’87 season was just not the same.” The Kings, by contrast, already had a lot of promising young talent on their roster.

Danny Ainge’s Bill Russell factor

There was another factor that helped to smooth Ainge’s transition from Boston to Sacramento: the presence of Celtics legend Bill Russell, who just so happened to the King’s general manager that season. Russell had discussed acquiring Ainge with his good friend and then-Celtics coach K.C. Jones.

Jones quickly sold Russell on Ainge’s talent as well as his potential contributions to the Kings team. The trade made sense for both teams and offered Ainge a great way to make his exit from Boston. Just the fact that he was going to a team whose GM was arguably the greatest Celtic of all time made the transition a lot easier than it might have been otherwise.

Things go sideways in Sacramento

Ainge’s excitement about going to Sacramento had a lot to do with the Kings’ roster, which seemed primed to go on a postseason run in the 1989-90 season. Unfortunately, things didn’t play out that way, thanks to a mixture of tragedy and bad luck. For one thing, promising young shooting guard Ricky Berry died by suicide during the 1989 offseason.

That loss not only hurt the Kings’ on a talent level but also in terms of team morale. To make things worse, the Kings’ draft pick Pervis Ellison — taken with the first overall pick — ended up missing 48 games of his rookie season due to injuries that would continue to plague his entire career.

Just like that, the Kings prospects seemed to collapse around them. The team ended up posting a dismal 23-59 record. It was clear that their future was now going to involve the same kind of laborious rebuilding process as the Celtics. The 31-year-old Ainge had no interest in sticking around for that.

Following the 1989-90 season, the Kings were gracious enough to trade Ainge to the Portland Trailblazers. Ainge spent two years as a backup guard in Portland, and then three years as a backup for the Phoenix Suns, before finally calling it quits. Fortunately, he had no hard feelings for the Celtics, who ultimately welcomed him back a decade later with open arms.