BOSTON — In a win-or-go-home elimination game in the Eastern Conference finals in 2021, the Hawks needed everyone. But a big game from forward John Collins gave an even bigger lift.

This year’s first-round series with the Celtics, who the Hawks trail 3-2 entering Game 6 on Thursday night at State Farm Arena, and this season, haven’t been kind to Collins.

Questions of whether Collins would remain in a Hawks uniform have come up at almost every turn. He’s shot the ball at the lowest of clips since his rookie season, and he has struggled to consistently hit numbers that garnered him his contract extension two seasons ago.

But Collins always is eager to show that he is the player who warranted the five-year, $125 million contract.

After averaging 7.5 points on 32.4% shooting from the floor and 21.1% shooting on 3-point shots over the first four games, Collins found the basket for four 3-pointers Tueasday. His fourth 3 of the game sparked the Hawks’ 17-6 run in the final five minutes of their Game 5 victory.

Collins scored seven points in that span and ended the night with 22, a series high for him. He also had two rebounds and one steal.

“It feels great,” Collins said. “I’ve been trying to sacrifice and do what I can for the betterment of the team. If that means not shooting the ball, there’s so much to create space or to just create offensive movement or whatever, I wanted to do that. So whenever I do get going, because it feels good, and (I’m) trying to keep it going.”

The Celtics have given the Hawks plenty to think about when it comes to matchups in this first-round series. Part of the sacrifice that Collins spoke of was being ready whenever the Hawks needed to adjust rotational matchups.

Ahead of Game 5, Hawks coach Quin Snyder talked of the Hawks’ need for nimbleness in the playoffs when it came to rotations. Snyder warned that Hawks needed to make sure that the Celtics’ rotational adjustments did not affect theirs, and at times they would want to initiate the changes.

So, Snyder said he told Collins that he would sub in Hawks forward Saddiq Bey if the Celtics went with a smaller lineup. If he wanted to force the Celtics to play a bigger lineup, he would keep Collins in.

During the Hawks’ outing in Game 3, Snyder rolled with Bey for the entire fourth quarter, and Collins played only 21 minutes in the game. He shot only 3-of-7 from the floor and 2-of-6 from 3. Throughout all of this, though, Snyder has encouraged Collins to continue playing with confidence and to stay aggressive.

“To our guys’ credit, that’s not always easy,” Snyder said. “And from my standpoint, those are really hard decisions. And you never know, you don’t get them all right. You just do your best. And I think guys are supporting each other in those situations, that is what matters the most, particularly in this environment because it does become matchup oriented.”

With Dejounte Murray missing Tuesday’s game after the NBA suspended him for his confrontation with an official at the end of Game 4, the Hawks needed a scoring punch to fill that void. Murray averaged 25.3 points, 7.3 rebounds and 5.8 assists per game, and Collins stepped in when many wondered who would fill the gap that Murray’s suspension left.

Now, the Hawks will continue to try to find ways to get even more players involved when they return to State Farm Arena. The Hawks have had guys go off in different games, with De’Andre Hunter dropping 27 points in the team’s loss in Game 4.

But to beat a team as deep as the Celtics, the Hawks will have to find ways to get as many of their starters clicking. They’ll also continue to lean on their bench, which has struggled at times in this series.

“You know we’re ultra-talented, extremely talented in a lot of aspects of the game,” Collins said. “(We’re) versatile defensively, and when we’re making shots, I feel like we’re a tough team to beat. So, if anything, resilience for us to, you know, go through those first two games, split at home, come back and get a road win, which is huge. Again, the resiliency of our team to continue battling is big time.”