Marcus Smart wasn't the best player on the Boston Celtics for most of his nine-year tenure, but he was undoubtedly the heart and soul of the team.

When the 29-year-old guard was dealt to the Memphis Grizzlies in a three-team trade to bring Kristaps Porzingis to Boston, the basketball world was in shock. Smart had been the team's longest-tenured player and embodied the hustle and grit Beantown expects from its athletes. Celtics head coach Joe Mazzulla emphasized Smart's importance on Thursday, making it clear that he's truly irreplaceable, per Jay King of The Athletic.

“You’re never going to replace a guy like him and everything he’s done on the court, what he’s done for his teammates and what he’s done in the community, for the city of Boston,” he said. “You’re just not going to replace that, so it’s not worth even thinking about that.”

Smart never missed the playoffs during his entire Celtics career and even became the first guard to win Defensive Player of the Year since Gary Payton in 1996. While in green he also made three NBA All-Defensive teams and helped the C's to their first NBA Finals appearance in more than a decade in 2022.

Away from basketball, Smart was just as impactful. He was close to the Boston community and held annual charity events to support children battling cancer.

At the end of the day though, the NBA is still a business. Smart did his best to get the Celtics closer to another championship, yet they never got it done. When the front office saw an opportunity to capture a third star alongside Jayson Tatum and Jaylen Brown, they made the tough call and offered up Smart.

Although Celtics fans will be saddened by the fact that the Texas native never got a ring in Boston, he's at least heading to a talented squad. The Grizzlies were the two-seed in last year's playoffs, yet for all their skill and athleticism they seemed to be missing a leader who would hold others accountable. With Smart, they now have that.

If the Celtics truly want to honor him, they need to prove that this big move was worth it and raise Banner No. 18. Anything less will be a disappointment for a sports town hungry for another championship.