Hayward’s abrupt absence has changed the point of view without altering the ultimate goal.

The Celtics still want to contend for championships. In the absence of Hayward, however, they can’t afford to reach for that outcome in the here and now -- not with so much to be learned and proved.

Will they be a defense-first team? An up-tempo, share-the-ball team? Those have been traits of Stevens’ preceding four seasons in Boston. But it’s too early to predict the future for this developing roster.

Kyrie Irving brings championship experience to a Celtics team stocked with youngsters.

Irving is averaging 20 points and shooting 37.5 percent as he adapts to his new surroundings. He is going to be judged by whether he can take pressure off his young teammates even as he pushes them to thrive ahead of schedule -- a passive-aggressive tack that LeBron James utilized while leading Irving and his fellow Cavaliers to The 2015 NBA Finals in their first season together.

The young Celtic most likely to flourish is Brown, the second-year swingman (and No. 3 pick of the 2016 Draft) who generated 25 points on opening night while overcoming the shock of Hayward’s gruesome injury. Brown has high hopes for himself across the board -- his long-term goals include serving as president of the NBA Players Association -- but Horford doesn’t want to see him trying to take on too much too soon.

“We just need him to do what he’s been doing,” Horford said. “He has that capability to be a great defender but also impact the offensive end. We want him to keep developing, to keep growing and improving, and make sure that we’re staying after him and he starts understanding how we want him to play. He’s been doing a good job of that.”

Though he has quickly become Boston’s No. 2 scoring option, the Celtics are encouraging Brown to look beyond the numbers.

“It should happen naturally,” said Horford of Brown’s statistical growth. “There’ll be some nights that he’ll have high-scoring games. There’ll be other nights that he’ll be doing more defensive work. I think it’s impressive because there’s not a lot of guys like him that are able to play defense and offense. He’s usually guarding one of the better guys defensively, and at the same time we’re expecting him to score the ball.”

Rookie Jayson Tatum has scored in double figures in three of his four games.

Tatum, the No. 3 pick last June, has been encouraged by teammates and coaches to hoist up shots.

“That’s the toughest part, me being a rookie and being out there with Al and Kyrie – instinctively I think, just give them the ball, even though I may be open,” said 19-year-old Tatum, who has also emerged as Boston’s No. 3 rebounder (7.8). “But it’s good for our team, when somebody’s open, to shoot their shot.”

The Celtics opened the second quarter Tuesday with a second-unit lineup meant to force-feed Tatum. Over the next 4:25 he sandwiched a pair of 3-pointers around a fade away, a transition assist, and a block that he turned into a full-sprint alley-oop as Boston stretched its lead out to 20 points.

Tatum, who was 1-for-5 from the arc through his first three games, hit 4 of 6 on Tuesday. In the first half alone, he and Brown combined for 30 points – three fewer than the Knicks.

“We don’t need them to do anything they don’t do well,” Stevens said. “We just need them to be good at what they do well.”

As Brown continues to invest in the details of his development – extra shooting, weightlifting, individual skills workouts and the like – he serves as an inspiring role model for Tatum.