The NBA thrives on rivalries, but few stories in recent memory have sent shockwaves through the league quite like Marcus Smart’s stunning move to the Los Angeles Lakers. For nearly a decade, Smart was the embodiment of Boston Celtics basketball — gritty, fearless, loyal, and unapologetically passionate. Now, he wears the purple and gold of Boston’s most hated rival.

And if that betrayal wasn’t enough for Celtics fans, Smart is also clapping back at Jason Tatum — the face of the franchise — reigniting old wounds that fans thought had healed.

This isn’t just a roster move. This is basketball heartbreak, betrayal, and theater at its finest.

From Bleeding Green to Bleeding Purple and Gold

Drafted sixth overall in 2014, Marcus Smart was supposed to be a Celtic for life. He became the team’s emotional leader and defensive anchor, the kind of player whose contributions went far beyond the stat sheet. Charges taken, loose balls dived for, and locker-room speeches that inspired comebacks — Smart was Boston’s heartbeat.

He won the 2022 Defensive Player of the Year Award, made three All-Defensive First Teams, and was the glue in a franchise built on hustle and pride. For fans, Smart was “their guy,” the one who embodied what it meant to “Bleed Green.”

So when he signed with the Los Angeles Lakers in July 2025 after a buyout with Washington, it felt like treason.

The Celtics and Lakers rivalry isn’t just basketball. It’s cultural, generational, and bitter. Boston’s 18 championships stand just one ahead of Los Angeles’ 17. To Celtics faithful, Smart’s move wasn’t just a career decision — it was betrayal.

“I’m Expecting the Hate”

Smart knew exactly what he was walking into.

“I’m expecting a lot of boos. I’m expecting a lot of hate,” he admitted during his Lakers introduction.

Those words were as much an acknowledgment as they were a declaration of war. He understood Celtics fans would never forgive him. But what he didn’t expect was shade from Jason Tatum.

The Rift With Jason Tatum

To understand the animosity, we need to rewind to November 2021, when tensions in Boston boiled over. After blowing a 19-point lead in a devastating loss to the Chicago Bulls, Smart publicly called out Tatum and Jaylen Brown.

“They don’t want to pass the ball,” he told reporters.

The words landed like a grenade in the locker room. Here was Boston’s emotional leader publicly accusing its two young stars of selfishness.

Jason Tatum, caught off guard, later admitted on J.J. Redick’s podcast that he was blindsided. “It caught me off guard for sure,” he said.

Though Brad Stevens worked quickly to smooth things over, the damage was done. Trust had been fractured.

Years of Professionalism, But Never the Same

On the surface, Smart and Tatum moved on. They shared the court, reached the 2022 NBA Finals, and eventually celebrated the 2024 championship — though Smart wasn’t on the roster to lift the trophy.

But insiders always sensed tension. What had once been natural chemistry now felt manufactured. Tatum praised Smart in interviews, calling him his favorite teammate, but the compliments felt rehearsed, not heartfelt.

And Smart never forgot that moment when his honesty cost him his place in Boston’s hierarchy.

The Trade That Opened Old Wounds

In 2023, Boston traded Smart to Memphis for Kristaps Porzingis. For the franchise, it was a strategic decision. For fans, it was ripping out the team’s soul.

Smart struggled with injuries in Memphis and later found himself buried in Washington’s rebuild. By 2025, he needed a fresh start — and the Lakers offered one.

But the timing couldn’t have been worse for Boston. After winning the 2024 championship, Celtics fans believed the culture Smart helped build had finally reached its peak. Instead, the man who laid the foundation would now wear the jersey of their sworn enemy.

Social Media Meltdown

When the news dropped, Celtics fans erupted online.

“Marcus Smart is a Laker. Being a Celtics fan right now is hell,” one fan tweeted.

Bill Simmons, Boston’s most prominent voice, posted a meme capturing the agony of seeing Smart in purple and gold.

Others described it like heartbreak. “This feels like you broke up with your girl and then you see her out with your brother two weeks later,” one fan said.

The pain wasn’t just betrayal — it was betrayal to the Lakers.

What It Means for the Lakers

For Los Angeles, the signing is about more than trolling Boston.

Smart brings exactly what the Lakers have lacked since their 2020 title run: defensive intensity, veteran leadership, and championship experience. Pairing Smart with LeBron James, entering his 23rd season, and Luka Dončić, the franchise’s new cornerstone, gives the Lakers a balance of offensive firepower and defensive grit.

JJ Redick, now Lakers head coach, praised Smart’s “winning plays” mentality. Analysts predict Smart will thrive as a defensive anchor, secondary ball-handler, and cultural leader.

The concerns? His health and shooting. At 31, with injuries limiting him to just 54 games over the past two seasons, durability is a major question mark. His career shooting percentages (38.8% FG, 32.4% from three) also raise spacing concerns.

But if Smart stays healthy, his presence could swing playoff series.

Celtics-Lakers Rivalry Reignited

The real drama, of course, comes when the Lakers face the Celtics. Twice a year, Smart will step onto the TD Garden floor wearing purple and gold. The boos will be deafening. The emotions will be raw.

Smart now joins the rare group of players who have suited up for both franchises — but unlike others, he’s still in his prime. His ability to impact championship runs means this rivalry has new life, new stakes, and new storylines.

Imagine Tatum driving to the rim only to be met by Smart taking a charge. Imagine Smart diving across the floor for a loose ball in front of the Boston bench. The tension will be electric.

Legacy at Stake

Marcus Smart’s decision will define his legacy. If he helps deliver a title to Los Angeles, Celtics fans may never forgive him. If his body breaks down, critics will say he chased rings and lost himself.

But for now, the NBA is buzzing. Smart’s journey — from Boston’s soul, to Memphis castoff, to Washington exile, to Los Angeles villain — is one of the most compelling sagas in basketball today.

And with Jason Tatum’s subtle shade still echoing in the background, the question lingers: was this really about basketball, or was it about broken trust?

Conclusion

Marcus Smart once symbolized everything Boston loved about basketball. Toughness. Loyalty. Heart. Now, he symbolizes betrayal.

His move to the Lakers has reignited the fiercest rivalry in sports, pitted him against his former teammate Jason Tatum, and left Celtics fans questioning whether the championship culture they celebrated in 2024 still belongs to them.

One thing is certain: when Marcus Smart takes the floor at TD Garden in purple and gold, the boos will rain down — and the NBA world will be watching.