The Celtics bet on Payton Pritchard this summer. After a frustrating third season in which his role diminished, he was promised a bigger one with the Marcus Smart trade. The Celtics backed it up with a contract extension.

But even after a strong preseason, the early returns weren’t positive. Pritchard went on a cold spell to start the season. In a five-game stretch, he went scoreless in four of them. In the other, he scored 15 but all of them came in the fourth quarter of a blowout win over the Pacers. On Friday, he admitted that doubt started to creep in.

“I think it started messing with me mentally a little bit,” Pritchard said. “But then I went back to what made me a great shooter in the first place. So I just dialed it back into that. It’s just kind of just a mental game. It starts to kind of affect you, start second-guessing shots. At the end of the day, you put in too much work. So I just believe in myself.”

That work and that belief carried Pritchard through a trying season last year. And it paid off again in Friday’s win over the Nets, in which Celtics coach Joe Mazzulla credited Pritchard with changing the game. Pritchard continued to rely on impacting the game in ways beyond scoring. He stayed active defensively. He made hustle plays. He crashed the offensive glass and came down with four offensive rebounds. And then – finally – the shots started falling again.

While this is the role Pritchard has desperately wanted, there’s been an adjustment period. He’s getting used to the second unit and some new teammates. He’s figuring out where he fits and how he can impact a game. But even through the struggles, he had full support from Celtics coach Joe Mazzulla.

“Joe came to me and he was like, ‘You’re going to continue to play,’” said Pritchard, who finished with 13 points on Friday. “It’s like, you keep impacting winning in other areas and that’s all that matters. Shots are going to fall. They’re going to make sometimes, but got to keep finding other ways, too.”

“I think I missed, what, 11 in a row, since the Indiana game? I’m not going to do that much. And they know that. I’ve shown through my career here with the Celtics that I’m not going to do that much. They just believe in me, keep going. But always trying to find an impact in other ways. Defensively, offensive rebounds. Any way I can help the team win.”

Pritchard was doing that and then some on Friday. There was the offensive rebound off his own miss that he turned into his own corner 3-pointer that pushed the Celtics to an 8-0 run in the first quarter. There was a steal in transition. There was the offensive rebound off his own free throw miss that led to a layup. Another offensive board that led to a Sam Hauser 3-pointer in the fourth quarter.

The 6-foot-1 Pritchard’s four offensive rebounds tied his career high and led to eight second-chance points for the Celtics.

“It’s just leaving an impact on the game,” Pritchard said.

There’s a different expectation now for Pritchard now that he has a new contract and an expanded role, but he’s trying to limit the distractions.

“To be honest with you, I have been off social media and I haven’t been looking,” Pritchard said. “So I figured people are like coming at me. But it’s part of playing in Boston and that’s what I like about it. So I wouldn’t want to play anywhere else. If I’m playing bad, I want to hear it, but I’ll get it back.”

Pritchard never panicked over his tough stretch. He’s been through slumps before. It’s part of being a shooter. He maintained confidence in himself. He knew he would get through the other side.

“Like this is just making me better,” Pritchard said. “This is part of the journey. You know, these slumps, I think at the end of the day will pay dividends and will make me a better player overall. Like I’m not hitting shots, so these last couple of games, I had to find other ways to impact it. So it’s making me an all-around player and not just a shooter. So it’s part of the game.”

The Celtics will obviously rely heavily on their talented starting five throughout the season, but Pritchard remains a valuable piece of their championship pursuit. There will be moments, like Friday, that they’re going to need him. While there have been valid questions about the depth of this team, Friday’s performance was a big step in the right direction.

“He can hit shots from the parking lot if you let him, and he also is a great offensive rebounder,” Jaylen Brown said. “So him playing well and him being confident in himself is going to be good for us down the line.”