The Celtics belong to Jaylen Brown and Jayson Tatum

Ime Udoka’s first effort to reach his Celtics players failed.

Roughly one year ago, the biggest story at Boston’s training camp was Udoka’s announcement that the team would name a captain for the first time since Rajon Rondo.

There’d be two, and after Kemba Walker’s departure during the offseason, the honor would almost certainly fall on the team’s pair of ascending stars. Marcus Smart defied the notion they needed one at all. Jayson Tatum seconded that sentiment. Jaylen Brown suggested Al Horford should take on the role. Soon, Udoka relented. There would be no captains.

Udoka later said his focus shifted from that to injuries and COVID instead of those honorary titles. After a season where he definitively emerged as the voice of the team instead of any player through public challenges, rallying cries from the team’s lows, intense film sessions and strategic emphases, interim head coach Joe Mazzulla is leaning on his stars as leaders in Udoka’s absences. They’ve answered so far.

“We’ve all grown,” Mazzulla said. “Failure helps that and I feel like over the course of last season, the way we started, the way we finished and how the season ended, we’ve all had great perspective about what we need to do as leaders and how we need to grow in that.

JT understands that and he’s a leader by example, committed on the defensive end and willing to make the right plays on the offensive end. So, I think you can say that for all our guys.”

Media Day cast uncertainty over the group. They couldn’t afford to waver or express any doubt about the transition under the national microscope. Sure, they all held legitimate questions over the process and details surrounding Udoka’s suspension, but Mazzulla emphasized the need to heal. He wouldn’t rush anyone into camp, but the players arrived eager to get started.

Some didn’t know what to think, still lacking information. Udoka’s ousting had the chance to derail the season before it began if those feelings lingered. What if players questioned Mazzulla’s ability to lead, or no voices filled Udoka’s former presence?

Tatum emerged on Day 1 and, along with Brown and Smart, crucially threw their support behind their new head coach.

“It’s a lot to process, unexpected,” Tatum said at Media Day. “Coming off last year, you’re excited, trying to do all these things. It’s a lot, and I guess along with everybody else, you’re trying to process it all knowing we still have practice tomorrow ... what I’m looking forward to most is just playing basketball. There’s been a lot of talking. Tomorrow we just get to play basketball ... (Mazzulla is) somebody we’re comfortable with ... somebody we’re familiar with and have a lot of respect for.”

Horford first noticed Tatum becoming more vocal during last year’s postseason — getting into teammates and challenging them through the team’s lulls. Tatum once said he’d lead in his own style, by example, and said he didn’t need to listen to anyone’s input on how he should approach that role.

At this training camp, Tatum’s acknowledging his budding presence in the room. He discussed how he approaches interactions with teammates differently than his understated media persona. He wore a mic for a session to show them off, jabbing at Grant Williams per usual and Sam Hauser, who he poked at over who the best shooter on the team is. Tatum quipped that Hauser should try to shoot like he does with the pressure he plays through.

The same way Brown and Tatum once shrugged off addressing their relationship before the lows of last season eventually made Brown and Tatum address it face-to-face. In a NBC Sports Boston interview at Media Day, they appeared alongside each other again, Brown turning to Tatum and asking — do you want to win? Tatum hesitated for a moment, then Brown set them straight. We want to win.

The Celtics don’t have a single voice. They embrace having many and letting anyone speak up when they see something. Grant took that pass and ran with it last season. Smart never hesitates to speak up. Having tone-setters publicly matters though, as Udoka showed early last season when players didn’t fight through pain, show mental toughness or maintain winning habits. Assistants who keyed that approach remain. The messenger is important.

Brown and Tatum have sounded willing to take on that role, but we’ll only learn the true potential of that leadership tandem when they need to hold themselves accountable following difficult losses. Mazzulla may not feel empowered to call them out yet.

“I think the biggest thing, this is what I believe, the more leaders you have in the locker room, the better your team is going to be, and I believe that our guys, in order for us to take that next step, we need to continue to step up as leaders, and leaders don’t have to be vocal,” Horford told CelticsBlog/CLNS Media this month.

“Leaders can lead by example, they can do different things and I believe that all of us have to do a little more to be a better group with the situation before, or what we have now. It really doesn’t matter, it’s all about us growing together, and I think that’s where we became better last year.”

“I feel like everybody took more ownership, and we did that. Now, it’s like a carryover in that area and we need to be better as a whole navigating through all the adversity.”

Opposite of Tatum, Brown found his voice earlier last season, challenging himself to speak up and demanding urgency from teammates. He arrived unimpressed to the podium after the Celtics thrashed the Hornets for 134 points on nearly 60% shooting to open the preseason. Don’t let the score fool you, he said, the Celtics needed to work on their defense, rebounding and more.

When the Celtics returned three nights later to face the Raptors, Tatum attacked the boards alongside Brown, an emphasis they set, and led a resilient effort protecting the glass. Brown spoke about strategies like spacing after the game and both he and Tatum left the uncertainty surrounding Udoka’s suspension in the past.

They’d focus on basketball in the aftermath of the Udoka suspension, and hit the ground running on both ends without Robert Williams III.

“I think we’re just picking up where we left off. Defensively, knowing when to make the right reads,” Brown told CelticsBlog. “And knowing when to make the right reads on offense. It all flows together. Right now, I feel like we’ve got a good chemistry, we’ve got to just keep building on it.”

Brown, shooting 23-for-39 in the preseason, stressed that he sees himself as a ball handler and approached Mfiondu Kabengele after a recent practice to work through pick-and-roll actions with him long after the end of the session. He coached Kabengele along the sideline through his screening during the Toronto game, showing an intention to lift up the two-way center as he tries to make an impact on the pro team.

Blake Griffin praised Boston’s maturity after he arrived and referred to the room’s atmosphere as one he hasn’t been used to in his career. Malcolm Brogdon felt similarly and wanted to make his voice heard without overstepping. Smart stated the importance of having familiarity in the head coaching role, a voice in Mazzulla who’s seen the Celtics at their best and worst since 2019.

“The guys in that locker room, when we’re in practice, on the plane, or on the court, my presence is felt. My voice,” Tatum said. “We all put a lot into this game. We all have the right to give input to each other, and that’s all I try to do when I see something.”