Now that the Boston Celtics are reigning NBA Champions, they have a target on their back heading into next season. Between the New York Knicks, Philadelphia 76ers, or even the Indiana Pacers, some of Boston's biggest Eastern Conference threats have leveled up this offseason, so if they try to swing at the kings of the NBA, they don't miss.

However, in the eyes of Celtics diehard Bill Simmons, the Knicks and 76ers aren't Boston's biggest threat in the Eastern Conference. Instead, it's the Milwaukee Bucks that keep Simmons up at night.

“I’m the most worried about the Bucks in the East,” said Simmons. “That’s where I’ve landed. I’ve had a little bit of vacation over the last few weeks. The Bucks are the scariest team to me; I’m not that worried about Philly; two of their top three are injury-potential guys, and they’re throwing a whole bunch of dudes together. I still have some questions about Paul George in Philly and how that’s going to play out over an eight-month span.

“The Knicks, there’s going to be some weird minute stuff with them bringing Randle back, with who’s going to finish games, they don’t have enough size, they’re really going to miss Hartenstein and are they going to get the same healthy season from Brunson. Then you have Milwaukee, which is going to be stable; you have Doc adding his coaching staff like Mazzulla did over last summer.”

So, although Simmons might have a bit of a bias since Milwaukee head coach Doc Rivers was a frequent friend of the program, his concerns about Philadelphia and New York could hold. But more than just Rivers adding new assistants this summer scares Simmons. It's also what the Bucks have been cooking up on the court.

Why Bucks are a threat to Celtics next season

Milwaukee Bucks forward Giannis Antetokounmpo (34) looks for a shot against Boston Celtics guard Derrick White (9) in the third quarter at Fiserv Forum.
Benny Sieu-USA TODAY Sports

To Simmons, nobody else has vanquished a healthy Giannis Antetokounmpo other than the 2022 Celtics, who vanquished them in seven games in the 2022 Eastern Conference semifinals. But Simmons admits that for Boston to beat them, it took otherworldly performances from Jayson Tatum and Grant Williams. At the same time, Milwaukee was hamstrung because Antetokounmpo was the only difference-maker for the Bucks in the series.

But now that Milwaukee has Antetokounmpo, Damian Lillard, and Khris Middleton at 100 percent, they can press the Celtics all season long and in the playoffs, especially after the Bucks added depth. Although Milwaukee is stuck deep in the second apron of the NBA's luxury tax threshold, they've added many high-quality bench pieces on veteran minimum deals, like Gary Trent Jr., Delon Wright, and Taurean Prince, who move the needle further for the Bucks.

Granted, it'll be a battle between who has the better on-court fit, and since Boston is more or less running the same team back, they have continuity against Milwaukee. But, if the Bucks meet the Celtics in the playoffs, it could be scary hours for Simmons and other Boston fans — especially if Antetokounmpo and Lillard are at full strength.