Heading into the Celtics’ first round series against the Hawks, Sam Hauser wasn’t even sure he was going to get a chance to play.

“Honestly, I didn’t know much going into the series,” Hauser said after Game 2. “You just have to stay ready and when your number is called, you have to make sure you are ready to go.”

Coach Joe Mazzulla had opted for an eight-man rotation as the regular season wound down and the historical precedent was that Grant Williams would get that nod as Boston’s 8th man as the playoffs began. However, a strong close to the regular season by the 25-year-old Hauser (42.6 percent from 3 after the All-Star Break) combined with Williams’ recent offensive struggles led Mazzulla to go with a more offensive-minded group for their matchup against Atlanta and that meant Hauser getting the nod.

“I think it’s just more we have a deep team, the ability to play a lot of different ways,” Mazzulla said before Game 2. “And we’re gonna need everybody if we want to win. And so, right now, versus Atlanta, the rotation we had gives us the best chance to win, we’ll continue to do that throughout the playoffs.”

Hauser has not done much when it comes to his own individual stats through the first two games of this series. He’s played 26 minutes in total and has gone 1 of 3 from 3-point range. However, the threat of his 3-point shooting combined with Boston’s stars has allowed Boston’s supporting cast (Derrick White, Malcolm Brogdon) to feast going into the paint with little resistance. Hauser has helped the group maximize their spacing and that’s led to a better offense as a whole for the team.

The Hawks have tried to make the Celtics pay for playing Hauser by putting a target on the forward’s back on the other end of the floor. Atlanta ran pick-and-rolls at him on countless occasions in Game 2, pulling him into switches on Trae Young and other speedier players. The net result was lackluster for Atlanta as Hauser more than held his own in those matchups. According to NBA.com tracking data, Atlanta went just 5 of 12 (41 percent) from the field when matched up against Hauser in Game 2. Young also turned the ball over two times when trying to take Hauser off the dribble.

On a team with few defensive weak links, the 6-foot-8 forward is no stranger to being picked on but he is embracing the opportunity this series.

“I kind of expected it,” Hauser admitted. “It’s kind of been happening all year long so it’s nothing I’m not used to or not unexpectedly going into a game thinking it’s not going to happen. I’m ready for it, I know that I’m going to try my best on it and I know my teammates have my back if I do make a mistake. That gives me confidence while I’m on the ball.”

The net numbers through two games with Hauser on the court indicate that his role won’t be changing anytime soon in this series at the least. He has the best net rating (+23.6) on the team in his limited bench minutes and Boston’s defensive rating with him on the floor (94.5 points allowed per 100 possessions) is the second-best on the team. The big question about Hauser all year long is whether he would be able to hold up defensively in these big moments and the early returns are promising on that front.

“Just really high attention to detail and connectedness on that side of the floor,” Hauser said of the Celtics’ team defense against Atlanta. “Every is talking, we’re playing tendencies and really sticking to what we’ve been talking about in our game plan and film sessions. We’ve executed it really well but we have to continue to do that over the rest of the series.”

Hauser is never going to win any defensive awards and may not ever even be considered an above-average defender in this league. His ability to hold court in a playoff game is a huge boon for this team though as it tries to stretch out opposing defenses with strong spacing. Bigger tests are looming in the rounds ahead that will put Hauser’s rotation spot in question but his performance so far is a sign that he’s been quite the steal for the front office (under contract for minimum money through 2025).

“It’s pretty cool,” Hauser said of his first meaningful playoff minutes. “First time for everything. I think I’m appreciative of the journey I’ve been on so far and I definitely am not taking it for granted.”

AWARD: The Boston Celtics asked Malcolm Brogdon to learn a new role. He mastered it quickly.

Brogdon was honored as the NBA’s sixth man of the year, after a season in which he came off the bench exclusively and helped the Celtics finish with the second-best record in the NBA.

It’s the second major individual award of Brogdon’s career: The 30-year-old guard was rookie of the year in 2016-17.

“This is such an honor. It has definitely been a transition for me, coming from Indiana to Boston,” said Brogdon, who had started every game the past four years in the NBA before embracing his role to come off the bench when he was acquired by the Celtics. “My last two seasons, they weren’t super successful, so for me that was another gut check for me in understanding that maybe I’m not a No. 1 guy but I can be a great No. 2, 3 or 4.”

Brogdon beat out fellow finalists Immanuel Quickley of New York and Bobby Portis of Milwaukee, receiving 60 of 100 first-place votes and 408 points overall from a media panel. Quickley was second at 326, getting 34 first-place votes. Portis had six first-place votes and 97 points.

Brogdon averaged 14.9 points, 4.2 rebounds and 3.7 assists; among those who played primarily off the bench this season, only the Los Angeles Clippers’ Russell Westbrook finished with better averages in those three categories.

The Celtics sent a significant package — five players and a first-round draft pick — to Indiana last summer for Brogdon, with this specific off-the-bench role in mind even though he had started in each of his last 210 regular-season appearances. He played in 67 games for the Celtics, all off the bench.

And he was still third on Boston in points per game, behind only All-NBA candidates Jayson Tatum and Jaylen Brown. When Brogdon made at least 50% of his shots from the field, the Celtics were 26-9 — and 13-0 when he shot at least 63%.

“Coming to Boston and playing behind JT, behind JB, these guys are proven All-Stars and soon to be All-NBA guys,” Brogdan said. “It’s definitely a good fit for me.”