That's the situation we're dealing with as the C's and the Boston Garden play host to Rivers' Los Angeles Clippers on Dec. 11, making it the first time the head coach has faced Boston since joining the franchise in 2004. Of course, it's a scene that will trigger plenty of memories.
After all, Rivers has quite a few highlights from his tenure with the Celtics. There are plenty of great moments, including—but by no means limited to—these 10.
From being hired by the franchise prior to the 2004-05 season to embracing one of his favorite players at the close of the short-lived 2013 playoff run, Rivers' time in the Garden was nothing short of remarkable.
He coached All-Star teams, won a championship and even joined an exclusive fraternity of Boston coaches.
But out of all the great memories, these 10 have to be the ones that rise to the front of his mind when push comes to shove. When he strolls onto the court in Beantown, think of these and the good times he provided rather than focusing on the bitter end.
Note: These moments are presented in chronological order, not ranked.
Doc Rivers wasn't supposed to be hired so quickly.
He had enjoyed an up-and-down tenure with the Orlando Magic, winning Coach of the Year during his first season in charge before making the playoffs the next year. After that, there was more of a roller-coaster ride, and then he was fired after a 1-10 start to the 2003-04 season.
All it took was one year off, as Rivers worked with NBA on ABC for the rest of the 2003-04 campaign before he was hired by the Boston Celtics. And the rest is history, even if he got off to a rocky start.
The C's made the playoffs in 2004-05, but then they fell back to third in the Atlantic Division the very next year, missing the playoffs as Rivers was thrust firmly onto the hot seat.
Remember this Bill Simmons column?
It begins as follows: "Doc Rivers stinks as an NBA coach. After watching him butcher my favorite team for 15 months and 134 games, I feel pretty comfortable making that assessment."
Getting hired by one of the greatest franchises in the NBA (arguably the greatest, depending on how you feel about the Los Angeles Lakers) was a great moment, but the first few years in charge most assuredly weren't. Boston fans can thank their lucky stars that Simmons isn't always right and loves getting hyperbolic.
Since his Boston Celtics had the best winning percentage in the Eastern Conference during the early portion of the 2007-08 season, Doc Rivers was selected as the East's head coach for the 2008 All-Star Game.
That's always a special moment for a coach, and it was the first such honor of Rivers' career. He'd go on to represent the East in 2011 as well, but you always remember your first time.
Although Kevin Garnett was unable to play due to injury, he, Paul Pierce and Ray Allen were on the squad. Rivers was right at home, just adding a few new faces to surround his star players. It remains unknown how much of an impact he actually had on the proceedings (probably not much), but the East did get a six-point win.
Full of festivities, the All-Star proceedings are always entertaining, especially for the central figures. That had to be the case for Rivers during the first of his two selections to the coaching staff.
Winning a championship is the pinnacle of an NBA career, both for players and coaches. When Doc Rivers got to shake David Stern's hand and hoist the Larry O'Brien Trophy, it was a moment of validation.
After years of struggling in the realm of mediocre teams while coaching the Orlando Magic. After years hearing criticism from Simmons and other fans of the Celtics. After acquiring Kevin Garnett and Ray Allen, then implementing his infamous "ubuntu" mentality.
He had finally arrived.
Boston made its first NBA Finals appearance since 1987, and it successfully took down the Los Angeles Lakers in six games. Game 4—a comeback from 24 points down in the third quarter—and Game 5—which featured a 16-2 run by the Celtics to tie things up in the fourth—will remain classics forever, and the six games as a whole will go down as one of the most entertaining series in recent memory.
But for Rivers, it was all about the final moment. The moment in which he could hold up the trophy and take a deep breath.
This just doesn't happen in the NBA.
Coaches get showered by Gatorade buckets so often in football games that we've started wondering why they're still surprised when they get soaked. But on the hardwood during an NBA game?
This was a unique moment, and it established just how jubilant Paul Pierce, Kevin Garnett and Co. were to win the 2008 title. It delayed the title ceremony, but something tells me that not a single person in the Boston organization cared.
Turning Doc Rivers' classy outfit into a wet, orange mess was worth it.
That's the only word that can be used to describe the first-round battle between the Boston Celtics and Chicago Bulls in 2009.
Rookie point guard Derrick Rose knocked down two clutch free throws, then watched as Paul Pierce went 1-of-2 at the stripe to force overtime. After Rose fouled out in the extra period, Tyrus Thomas took over and put the Bulls in the driver's seat.
But that was by no means the end of the drama.
After Boston won Games 2 and 3, Chicago took Game 4 in double overtime. All of a sudden, the series was knotted up. And it wouldn't get easy for either team.
Game 5 somehow went to overtime, despite Chicago getting out to a big second-half lead. Rajon Rondo finished as the high scorer in the game, but it was Paul Pierce who led the Celtics to that win, as well as numerous great play designs from Rivers. That was already three overtime periods in five games.
The total was doubled in one fell swoop when Game 6 rolled around.
Fifty-one points by Ray Allen almost stole the show, but Boston emerged with a 128-127 loss. Fortunately for Rivers, the C's would close out the epic series with a home victory in Game 7, advancing to the next round and sending Chicago home in heartbreaking fashion.
It's a series that no one involved will ever forget.
A year after the emotional victory against the Chicago Bulls, Doc Rivers and the Boston Celtics squared off against the Orlando Magic in the 2010 Eastern Conference Finals.
Boston won each of the first three games, highlighted by taking back-to-back outings on the road and then holding Dwight Howard and the Magic to only 71 points in Game 3. The Magic would storm back, winning each of the next two contests, but it wasn't enough.
Behind 31 points and 13 rebounds from Paul Pierce—both of which were game highs—the C's knocked the favored Magic out in six games and advanced to the NBA Finals. The Lakers were waiting for them and would eventually take down their bitter rivals in Game 7, but that's a different story.
This was a great moment for Rivers because he advanced to the NBA Finals (again) but also because it was an upset victory (Orlando won nine more games during the regular season) that came against his former team.
Just watch the video.
Glen Davis' laugh says it all.
Austin Rivers had one of the worst rookie seasons of all time, but he still helped produce a great memory for his father.
It had to be a special moment for Rivers to stand on the sideline and watch his son play for the New Orleans Pelicans. That only happened once during the Duke product's rookie season, as injury kept him out of the second scheduled matchup.
And yes, this is a great moment for Doc, even though he and the Celtics lost the game. Behind a rare semi-efficient outing from Austin and a balanced offense that saw five players hit double figures, New Orleans emerged with a 90-78 victory.
Austin finished with eight points on 3-of-6 shooting from the field and added one assist to his line. He was also plus-12 when on the court.
Doc finished with a loss and a lot of pride in his heart. That has to count for something.
"We're fighters, we're a team that's going to compete for 48 minutes. It's not always pretty and we're not perfect, we're human beings and we play hard."
That's what Kevin Garnett had to say, via NBA.com, after dropping 27 points and 10 rebounds in the 99-95 Boston victory over the Toronto Raptors on Feb. 6, 2013. It's accurate both for that night and the entirety of Doc Rivers' tenure with the team.
Nothing was ever perfect, but Rivers consistently motivated his troops and maximized what they gave him. However, this game was significant for more than just the aforementioned KG quote; it gave Rivers his 400th victory as the coach of the Boston Celtics.
He joined Red Auerbach and Tom Heinsohn as the only members of the 400-victory club, and he'd go on to extend his total to 416 before moving on to the Los Angeles Clippers.
Think about it a different way now.
In NBA history, only 42 men have recorded 400 career victories, regardless of the team for which they call the shots. Rivers joined the fraternity during only the Boston portion of his NBA tenure.
According to Yahoo! Sports' Adrian Wojnarowski, the final embrace between Kevin Garnett and Doc Rivers, one that occurred in the waning minutes of the season-ending loss to the New York Knicks, went something like this:
This is the reason the tears welled within his eyes beneath that 17th championship banner in the Garden on Friday night, the reason that he squeezed Garnett on the sideline in the final seconds.
Deep down, Doc Rivers and Kevin Garnett understood this was goodbye.
Deep down, they know it is over.
"I love you," Rivers told Garnett.
"I love you," Garnett told Rivers.
It was a poignant and emotional moment, one that had to leave Celtics fans feeling warmer inside than they otherwise could as they reminisced about what these two men meant to each other. It was a moment of mutual respect, admiration and love, as much as a player and coach can ever share.
For Rivers, it was never just about building resumes and winning games—it was also about developing healthy and meaningful relationships.
That came to a head during the final minutes of his final game with the Celtics.