BOSTON — Brook Lopez is on a pitch count.

The Nets’ best player — like the entire roster, according to coach Kenny Atkinson — is having his minutes closely monitored already, just one game into the season. After a subpar preseason, Lopez opened the regular season by logging just 21:12 in Wednesday’s 122-117 loss to the Celtics, including 9:12 in a second half that started with him on the bench.

“What we’re trying to do with Brook is take the long-term approach, just build him up as the season goes on and increase his minutes. We have a plan in place,’’ Atkinson said. “It’s learning the system, it’s looking at a long-term approach to how we’re going to build him up in terms of minutes as the season goes on. He’s got some miles on him.”

Lopez said the comparison of a pitch count is fair. “That’s a pretty good metaphor for it,” he said.

But considering his struggles to fit into the motion offense this preseason, mustering just five points on 1 of 7 shooting is sure to raise eyebrows — especially in a game where the Nets put up a team-record 44 3s and he gave a referee an earful.

“Obviously it was a difficult decision to come to for me because I love being out there on the court and helping my team. But I understand the reasons for doing it,’’ Lopez said. “We talked about it and discussed it a lot, and felt it was for the best. I’m on board with it, and I see the benefit of doing it in the long run.”

Backup center Justin Hamilton had 19 points on 7 of 12 shooting, 3 of 6 from deep. Atkinson praised Hamilton as a “system fit.”

Shooting guard Bojan Bogdanovic — who didn’t make a start in the preseason as the Nets eased him back in after a grueling Olympic summer — had a team-high 21. He hit a late 3 to get the Nets within 120-117, but missed a potential 3 to tie.

“I feel like it was going in, especially because I made the one before. We got two great looks, me and Justin on the last play,’’ Bogdanovic said. “It’s our job to get better in the game but also when you [give away] 23 points on the road it’s tough to win.”

Jeremy Lin – who played four years at Harvard and graduated in 2010 — donated $1 million to his alma mater, in support of undergraduate financial aid and renovations to the school’s basketball arena.

“Without question, my time at Harvard prepared me well for success both on and off the court,” Lin said in a statement. “I’m honored to put that same world-class education in reach for deserving students and to support improvements to the facilities where I spent countless hours practicing and competing.”

Lin, who had 18 points and three assists, signed a three-year, $36 million deal with the Nets this offseason.