The team has made a nearly flawless transition from an aging team coming off a championship and little cap room into a legitimate contender in the Eastern Conference.
Boston is poised to secure its eighth playoff appearance in the last nine years, while also collecting the most impressive arsenal of future draft picks.
With a 32-23 record at the All-Star break — the third best in the Eastern Conference behind only Cleveland and Toronto — while paying the 14th highest salary in the league.
The Celtics even have the ability to completely revamp their roster again this summer, if they elect to, as the team has just $27.6 million committed to next season.
Only the Lakers, 76ers and Trail Blazers will have more cap space than Boston this summer.
Nearly every move President of Basketball Operations Danny Ainge has made, from his hiring of Brad Stevens, to the timing of trading away Rajon Rondo and landing Isaiah Thomas just two months later, has worked to perfection.
A year after landing Thomas, and molding him into an All-Star, the Celtics face a different dilemma as Thursday’s trade deadline approaches: they have too many future assets.
The team needs to cash in for a superstar, if not today, then before the 2016 NBA Draft.
In the first round alone this season, Boston has its own selection, along with the rights to choose in place of the Nets and Mavericks.
If the team retains all of its draft picks, the team would add eight rookies to its roster this June.
Having so much young talent on one roster is simply unrealistic, so as the league has less than 24 hours to complete a deal, the Celtics are suddenly the most intriguing team in the league.
Flush with 2016 NBA Draft selections, expiring contracts and versatile players, Boston can influence numerous deals Thursday afternoon.
The Celtics landed Lee just days after Golden State won its first title in 40 years. Lee fell out of the Warriors rotation as Draymond Green emerged as a Defensive Player of the Year candidate.
The crowded front court of Boston, as Jared Sullinger, Amir Johnson, Kelly Olynyk and Jonas Jerebko have all logged more minutes at the power forward position, has forced Stevens to keep the two-time All-Star on the bench.
Even as the Celtics are wrapping up blowout victories, Lee has remained on the sidelines.
“I’m not gonna put him in there for five minutes or four minutes at the end of a game. He’s a really good player. The reason that he hasn’t played is a style of play choice, not a choice with any particular skill set by a particular player,” Stevens said. “He’s handling it like a pro, but that’s just a choice that I’ve made in the ends of those games in those situations.”
Lee hasn’t played in 18 consecutive games and has averaged just 15.7 minutes in his 30 appearances with the Celtics.
Along with the expiring $15.4 million contract of Lee, what makes the Celtics the most appealing trade partner is the first round selection from Brooklyn it possesses.
The 14-40 Nets are tied with Phoenix for the third worst record record in the NBA, giving the pick Boston owns a 13.75 chance of becoming the top overall pick in the NBA Draft lottery.
The emergence of LSU forward Ben Simmons as the top draft prospect could be enough to entice the Cavaliers, Clippers, Rockets or Hawks into striking a deal, instantly improving the Celtics roster.
Boston was anticipating a lengthy rebuild, but instead, the team missed the post season just once after dismantling the pieces from its 2008 championship team.
With plenty of trade assets, the Celtics could land the key piece for their 18th championship team as soon as Thursday afternoon.