Payton Pritchard is 10th in a nine-man rotation, but he sure came through for the Celtics this week

Payton Pritchard (left) was on the ball, especially in guarding Nets forward T.J. Warren in the second half.Mary Altaffer/Associated Press

NEW YORK — The opportunities are scarce, so Payton Pritchard has to capitalize on every moment on the floor. He’s the 10th man in a nine-man rotation, a player that many NBA teams covet but he’s on a championship-contending team that has made depth a priority. So his playing time has been sporadic for the past year-plus, and he has been assigned the arduous job of playing only when necessary. He doesn’t get 10-minute stints to get the rust off; he has to perform.

Pritchard played a total of 6 minutes, 21 seconds over a three-game stretch before logging 18 minutes Wednesday night in Marcus Smart’s absence.

A night later when the Celtics were missing Jaylen Brown, Pritchard again was summoned to supplement the bench and play key minutes against the Nets.

Pritchard provided a major spark on a night when Jayson Tatum was subpar offensively, scoring 9 points with 3 rebounds and a steal in his 14-plus minutes. He was a plus-13 in the Celtics’ 109-98 win, again proving his value to the team even though he doesn’t get the chance to make that point as often as he likes.

Pritchard acknowledged he has heard trade rumors. He earns a modest $2.2 million this season and is eligible for a rookie extension this summer. The Celtics would have no shortage of suitors for Pritchard, who has the ability to play point guard, shoot from the 3-point line, and is an exceptional rebounder for his size.

“Obviously I hear it, I see it,” he said. “I know what it is. But that’s not something I can focus on. I’ll let my agent handle that and Brad [Stevens]. I’ll focus on basketball.”

Pritchard made a surprising impact during his rookie season in Stevens’s final year as coach. He had a steady role as backup point guard and proved to be a late first-round steal. But his role and minutes diminished last season under new coach Ime Udoka and he struggled when he did get a chance, especially in the playoffs.

In six NBA Finals games, Pritchard shot 30 percent and averaged 2.7 points. Not much has changed this season, with the Celtics acquiring Malcolm Brogdon as the primary guard off the bench, giving Pritchard even less of a chance to prove himself. He’s averaging 10 minutes per game with 14 DNP-CD this season.

“This is a roller coaster of emotions for sure,” Pritchard said. “I think it’s just maintaining, not letting yourself get too low and never letting yourself get too high. It’s definitely been a huge learning experience for me. But for me, I just show up every day and work on my craft. That’s the only way I can focus on getting better, is keep working.”

Pritchard was a plus-13 in the Celtics’ 109-98 win.Brian Fluharty/Getty

Coach Joe Mazzulla said Wednesday Pritchard just needs to stay prepared for his next opportunity. It’s difficult to prepare when there is no certainty about playing time.

“As for Payton, I’m really happy for him,” Mazzulla said. “He’s maintained a level of professionalism, preparation and just toughness to just stay the course. [The reserves] did a great job. I think we showed what our team can be regardless if we’re whole with our depth, our mind-set, our toughness.”

Pritchard realizes he’s auditioning for the other 29 teams as well as playing for the Celtics. He’s watched Stevens trade away the organization’s past few first-round picks to get veteran players. Aaron Nesmith and Romeo Langford are gone, replaced by established veterans to help the Celtics win now.

What’s more, the Celtics drafted a potential point guard replacement in 20-year-old JD Davison, who is sharpening his skills in the G League and may be prepared for a rotation spot next season. Knowing the Celtics are one of the league’s deeper teams, Pritchard’s teammates said they encourage him to stay upbeat.

“I think that’s why when he gets this opportunity he does it so well,” guard Marcus Smart said. “Because he is so professional and he does all the right things to stay ready. That’s Payton. Payton comes in every day and he works like he’s a rookie. When you’ve got a guy like that, his time is going to come.”

It’s going to come, but it may not be in Boston. The NBA is a business and Stevens has promised to upgrade the roster for another Finals run, if necessary.

“I’m constantly telling Payton every day, as bad as it may sound, it’s the truth, it’s reality, you have to live in reality,” Smart said. “You’re not playing on this team. You’re not getting the moments that you want and you think you deserve because we’re so stacked. But there’s 29 other teams watching you and they understand your situation. They want to see how you handle this. I constantly tell him, when your time is called, you go up there for your opportunity, take it because you might not ever get it again. That’s all we ask for Payton.”

Pritchard is a luxury for the Celtics, a talented player who can spark the club on defense and offense. But that’s what Stevens learned from the Golden State Warriors: pack the roster with skill players, let them fight it out and beat teams with waves of talent.

The Celtics outlasted the Nets because of their depth and Pritchard is part of that depth, so he’s learned to accept his unpredictable opportunities and he’ll have to perform when they arise.