BOSTON — Terry Rozier has the doubters on an audio loop, and usually they talk about who won’t be on the Celtics roster when they open the playoffs Sunday against Milwaukee.

“There’s been a chip on the shoulder since (Gordon) Hayward went down,” the Celtics point guard said. “It sucks to see your brothers go down – (Marcus) Smart, (Daniel) Theis. Kyrie (Irving), Hayward, but like I said, it’s not over. It’s not going to be an easy road for our opponents. They still have to go through us. We’re ready.”

Boston enters as the No. 2 seed, but it is certainly vulnerable opposite a seventh-seeded Bucks team with which it split four games this season.

“It’s forcing our group to grow up quicker than maybe some of our guys were supposed to,” forward Al Horford said. “I think that this is a great opportunity that we have in front of us. We’ve really worked hard all year to put ourselves in this position.”

Who more so than Rozier? He’s played the best ball of his career this season, appearing in 80 games (16 starts) and averaging career highs in points (11.3), rebounds (4.7) and assists (2.9).

Plus, there’s an unusual parallel between now and Rozier’s first playoff series as a rookie in 2016. His playing time jumped as the result of a season-ending hamstring injury suffered by Avery Bradley in Game 1 of the first-round series against Atlanta.

Injury has expanded Rozier’s opportunity again, this time as the result of Irving’s knee surgery. But this time Rozier is the lead guard, responsible for running the offense against Milwaukee’s great point guard, Eric Bledsoe.

It will be viewed as Rozier’s greatest challenge to date, and he loves the chance, coming as it flies in the face of all those doubters.

“I got to control the game, basically just filling what a point guard is supposed to do – filling Kyrie’s shoes as much as I can,” he said. “Sometimes it might mean taking tough shots and making tough shots. … Do what I can to give this team a boost and put us in position to win.”

Unlike when he was a rookie pushed onto the proving ground against the Hawks in 2016, Rozier is now running the offense. He’s thrived as a starter, and admittedly sees the floor now with a clearer, slowed-down view.

“It’s just basketball to me. When I first got here, you’re just learning the game, and sometimes you think you got it, and sometimes there’s always more to learn of course,” he said. “But right now I’m just trying to be effective as much as I can and help this team win.

“We push the ball and I feel like we’re tough to guard. We have a lot guys who can push the ball, who can play with fast pace. If we do that, we’ll be a tough team to guard.”

And just maybe, Bledsoe will have his hands full.

And maybe, it will give the rest of the Celtics the opportunity to focus on Giannis Antetokounmpo, the 6-foot-11 superstar forward. Antetokounmpo is entering his third postseason and already has turned into a marquee player. He averaged 33.5 points this season against the Celtics, more than any player. His next step is to lead the Bucks to a victory in a playoff series.

“Right now, (the) playoffs is not about stats. It’s all about winning,” Antetokounmpo said. “It’s going to be a long road. We’re going to try to go to the end.”

Trying to slow him must be a team effort, Celtics Coach Brad Stevens said.

“We’ll have to guard him with everybody on our team,” he said. “It’s not on one person to guard Giannis. We have to throw a lot of different bodies at him.

“The way I look at it, we’re not going up against him – we’re going up against the Bucks,” he said. “A guy like him, we have to be able to contain him as a unit, and that’s our mindset.”

The Bucks have a number of other threats, including Malcolm Brogdon, last season’s rookie of the year who returned Monday after missing 30 games with a partially torn quad.

“Giannis, Jabari (Parker), (Khris) Middleton, they’ve got a number of very good players,” said Stevens. “Obviously, that’s how we’ve tried to guard all year, is playing together, playing on a string. We’ve had our moments where we’ve been really good, so obviously we’re going to have to be very locked in to make it as difficult as possible.”