But there were challenges as the playoffs approached. Irving had to make sure that his teammates believed they could still be great, and he had to make sure they also understood what it would take to ascend when the games matter most.

MILWAUKEE — Even though the regular season did not unfold the way the Celtics had hoped, they knew all along that they would be in the playoff field. And amid all the angst surrounding their position in the middle of the pack, Kyrie Irving had an unwavering belief in what his team could be capable of, even from that spot.


“Kyrie has been in our ear, even weeks before the regular season ended, about the commitment and what we needed to do as a group, and how we needed to prepare and be better,” forward Al Horford said.

“I think that all the guys understood what he was trying to tell us and have taken up on that challenge in trying to be better and trying to do the little things to get us to this point.”

Horford said that Irving’s message did not come during a singular rah-rah players-only meeting, or a team flight, or anything like that. Instead, it has been gradual and consistent, spread across practices and postgame sessions. He has addressed the group and also pulled players aside and offered individual tips and encouragement.

He wanted them to understand that the final games of the regular season required more urgency.

He wanted them to understand that there was value in taking extra shots and getting extra medical treatment.

He wanted them to understand that they had to eat better and sleep more.

And he wanted them to understand that during this time of year these kinds of things, things that can sound trivial, are anything but.


“It’s great to be around him,” center Aron Baynes said, “and everyone is feeding off of it.”

Celtics coach Brad Stevens said Irving has shown leadership throughout this season, but he could see something a bit different when he addressed the team at a March 28 practice. The following night, Irving hit a buzzer-beating game-winner against the Pacers that helped secure home-court advantage in the opening round of the playoffs.

“You could kind of sense there was a little bit more of, ‘All right, it’s go time,’ in a lot of ways,” Stevens said. “Obviously, we rode a lot of ups and downs all year, but that can be part of your path to get to the best version of yourself.”

Irving is a superstar who has appeared in the NBA Finals three times and won one championship. His teammates said he does not regale them with stories from those years alongside LeBron James, but those experiences give his suggestions instant equity.

“He’s really been trying to get us to understand that this is not going to be easy,” Jayson Tatum said. “I listen to everything he says. He won a championship and we were close to getting there, so we understand we need that extra gear to get that much closer together.”

Last year, Terry Rozier thrived as a starter in place of the injured Irving, helping guide the Celtics within one game of the NBA Finals. Now that Irving is back, Rozier’s role has been reduced, but he said Irving’s tutelage has helped him embrace his standing on this team and search for ways to help.


“I feel like he just brought us closer together and put everything that we went through during the season aside and made sure everybody understands the importance of the ultimate goal,” Rozier said. “That helped us all, and we’re all on the same page right now.”

Of course, all of this advice and instruction could ring hollow if it were not accompanied by powerful play.

But Irving has taken care of that part, too.

He is averaging 23.2 points, 8.4 assists, and 5 rebounds in these playoffs, and the Celtics will bring a 5-0 postseason mark into Game 2 of their conference semifinal against the Bucks on Tuesday night.

Boston has won 11 of its last 13 games, and at least some of the uptick can be credited to Irving’s counseling.

“I think with the playoffs nearing, Kyrie felt like our sense of urgency needed to pick up as a group,” Horford said. “One of the things he made us aware of and challenged us to do more to prepare for these moments, making sure that we’re taking care of ourselves, that we’re doing the work we need to do.

“I think it resonated with our group and it was positive. I just feel like we all took on that challenge.”

Adam Himmelsbach can be reached at adam.himmelsbach @globe.com. Follow him on Twitter @adamhimmelsbach.