BOSTON -- On ESPN’s The Jump recently, Boston Celtics guard Marcus Smart delivered one of those straight-no-chaser sermons on the state of the team during the Kyrie Irving era and why he was so adamant about defending him.

The incessant dumping on Irving for what ailed the Celtics, the new sport of choice in New England this summer, was not part of Smart’s monologue as he portrayed the ex-Celtic in a very different light than the stories you keep hearing about now that Irving is in Brooklyn.

In listening to Smart talk about the past, you can’t help but think about its impact on this team’s future.

Throughout most of Irving’s time in Boston, the one thing that seemed to be questioned over and over and over again about him and his time as a Celtic was his leadership.

Now that he’s gone, all is good on the leadership front right?

Nope. Not even a little bit.

Because as big a blow as it was to lose Irving along with Al Horford via free agency and Aron Baynes via trade, their collective departures did more than just leave a gaping hole in terms of talent.

It has also left the Celtics in a place of uncertainty when it comes to leadership.

Yes, seeing head coach Brad Stevens and Jayson Tatum at a New England Patriots practice provided some nice optics as far as Tatum being on the same page as Stevens, which is one of the first chapters you come across when it comes to NBA Leadership 101.

But this group requires a certain kind of leadership, the kind that no one has a real sense exists, or for that matter, will come into existence when it matters most.

That’s because the way this roster is built, leadership is going to be a work in progress for all involved.

And while last year’s team may have been better talent-wise from top to bottom, the leadership potential for this group is so much greater.

For starters, there’s a much clearer level of accountability for all involved who contribute to both the team’s success and struggles.

When you hear Marcus Smart talk about Irving and last season, he has consistently kept the talk about how it wasn’t just one man (Irving) responsible for all that went wrong, but the team as a whole.

And when he has played poorly, he has not been shy about owning it, something that needs to trickle down to the rest of his teammates this season.

Boston also needs a leader who can find that balance between being demanding of himself and others, while understanding the need to be encouraging at times.

Smart has shown growth in this area and without question, has to be one of if not the front-and-center leader of this team.

Kemba Walker coming in should help, too.

He’s not nearly as outgoing as Smart is when it comes to leadership. But a source close to Walker says that his leadership style has a lot to do with timing.

“It’s kind of like his game,” the source told NBC Sports Boston. “He picks his spots when to speak up, when to let something slide and handle it inside the locker room, or when to just let it go.”

That will certainly be a change from what we’ve seen the last two years.

But how much will it impact winning?

“The thing is, Kemba has great respect for Marcus (Smart), Jayson (Tatum), Jaylen (Brown), all those guys because he’s seen up-close how hard they compete and how they push each other in games to get better,” the source said. “The real test will be in those rough stretches when they lose three or four in a row, five out of eight, stuff like that. That’s when you’ll see Kemba’s leadership shine through.”

The Celtics will need it, for sure.

Because as much as we can talk about the questions surrounding this Celtics team and their talent, figuring out the direction of the team’s leadership is arguably just as important and will be just as impactful on the bottom line, which is always winning.

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