Celtics summer league observations: Defensive pressure a new emphasis?

New York Times

21-07-2025

Baylor Scheierman ramped up the defensive intensity further after tapping the ball away from Miami Heat wing Keshad Johnson early in the first quarter of a summer league game last week.
Sensing the ball could be his, Scheierman rushed up on Johnson near half court to make another attempt at a steal. With the shot clock dwindling for Miami, Scheierman poked the ball away from Johnson again, then dove on the floor to secure possession. From his backside, Scheierman fired a long assist to Jordan Walsh for a fast-break dunk.
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The pass made it one of Boston's top highlights at summer league, but the defensive pressure that led to it might have been more telling. After years ranking near the bottom of the league in forced turnovers, the Celtics channeled a more disruptive style in Las Vegas, where they wrapped up summer league Sunday night with a 101-80 win against Atlanta. And that style could be indicative of how they want to play when the regular season arrives in October.
'I know that an emphasis is to force turnovers and to be more aggressive,' said Walsh. 'Whether that's a change going into this year because it's a new team or whatever the case may be, I know that it's going to be an emphasis.'
Forcing turnovers hasn't always been a primary emphasis in recent years. It's been one of the few glaring weaknesses in the Celtics' statistical profile since head coach Joe Mazzulla took over. Although Mazzulla constantly preaches the importance of the possession battle, his team has effectively punted on one of the ways to win it, finishing no higher than 24th in opposing turnover percentage during any of his three seasons as head coach. Even after Mazzulla pointed out the problem, stating before his second season he wanted to fix it, his team was never able to achieve the extra level of agitation he desired. He eventually dialed back his club's defensive coverages, deciding that staying solid worked best for the group.
It was evident, then, when the summer league squad harnessed a different type of energy. While summer league coach Matt Reynolds said 'every team' dials up the pressure in Las Vegas, he also hinted that the Celtics' change there could be more lasting.
'We see, particularly with the roster that we have here and some of the players that we'll have in the fall, we can force turnovers, we have multiple effort players,' Reynolds said. 'So that ball pressure and activity is obviously beneficial and that's something we want to do.'
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Over recent seasons, the Celtics have survived their inability to force turnovers by routinely controlling other statistical categories. Their astronomical 3-point attempt rate draws the most attention (as free-agent acquisition Josh Minott said, 'they shoot a s— ton of 3s'), but they have also taken care of the ball as well as any other team and have regularly finished among the league leaders in defensive rebounding rate. They haven't been a great offensive rebounding team, but stopped ignoring that aspect of the game over the last couple of seasons, with Mazzulla consistently emphasizing a higher crash rate. He is obsessed with winning the possession game.
That's one reason why the Celtics' inability to create turnovers over the past few seasons has been flummoxing. Changes could be coming, though, if summer league serves as any sort of indicator.
'We're picking up full-court, trying to wreak havoc on the defensive end of the ball,' said Scheierman. 'Maybe taking a little more gambles than we have in the past.'
Roster changes will likely force Mazzulla and his staff into some stylistic tweaks. With Kristaps Porziņģis and Luke Kornet gone and Al Horford likely to follow them soon, the Celtics have lost a lot of rim protection. Now with an iffy front court of Neemias Queta, Luka Garza and Xavier Tillman, they won't always be able to rely on their back line to save them. The Boston defense also took severe blows on the perimeter with Jayson Tatum injured and Jrue Holiday traded. Though the Celtics still have some highly capable defenders, including Derrick White, they simply don't have the type of roster they're used to with the ability to hold up one-on-one at every position. Maybe gambling a bit more would help.
If the Celtics needed any more reason to focus more on forcing additional turnovers, they recently watched the Thunder ride a ball-hawking, all-out-pressuring defense to a championship. Oklahoma City's ability to dominate the turnover competition on both sides of the court provided a significant margin for error throughout the team's title run. In a copycat league, every team will be looking to draw from the Thunder's approach.
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It's not like the Celtics have had a leaky defense. They have finished top four in defensive efficiency in each of Mazzulla's three seasons as head coach. They just haven't forced many turnovers during that stretch. Though it's never wise to overreact to anything that happens at summer league, the Celtics seem motivated to address that weakness.
'I think that we understand people are going to do the same thing to us,' Walsh said. 'So it's kind of like hitting somebody before they hit you. I think that if we're the aggressor, like, if you're met with force, you're either going to move out the way or you're going to meet them with more aggression. And so our approach was let's meet them with more aggression: harder, faster, more aggressive than they are so that we throw them off balance.'
The rest of the most important Celtics summer league takeaways follow below.
After getting ejected early in the loss to Miami, Walsh walked over to Celtics GM Brad Stevens as soon as the game ended. Walsh said sorry to his boss for losing his cool.
'I just wanted to apologize to him just because that's not really me,' Walsh said. 'I'm more of a professional than that. I'm more mature than that. So I just wanted to make sure he knew that and this wasn't going to be a continuous thing.'
Walsh didn't need to apologize to Mazzulla. Why? Because Mazzulla enjoyed seeing the passion in his young forward. By the time Walsh checked his phone following the ejection, Mazzulla had already texted him to say, 'I love this out of you.'
The differing reactions were predictable. Stevens is level-headed. Mazzulla seemingly wouldn't care if his team ripped off an opponent's level head. The two men are alike in some ways, caring about many of the same values, but they have opposite approaches to confrontation. Maybe the organization needs both types of leaders.
'Joe liked it,' Walsh said. 'I don't know if Brad liked it.'
Charles Bassey had one of the stranger Celtics summer league stints in recent years. He wasn't on the initial roster, but joined the team early in training camp. After he played in each of the first three games, the Celtics announced to the reporters still in Las Vegas that he had left the team, his deal was only for those three games and he had other commitments in the summer.
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Before his exit, Bassey was extremely productive while averaging 15.3 points, 11.0 rebounds and 2.0 steals per game. He lived up to his billing as an elite offensive rebounder and finished lob after lob thrown his way. The 24-year-old, who played for the Spurs last season, has dealt with some serious injuries throughout his career. He looked healthy in Las Vegas, though, and would represent an interesting flier for a team like Boston with limited frontcourt depth. To make that happen, the Celtics would need to do some roster maneuvering, as they currently have 15 players on standard contracts (the league maximum) and sit slightly above the second apron. Bassey is not eligible to sign a two-way contract because he already has four years of NBA experience.
One day after opening the summer league with a 2-for-14 shooting performance, Scheierman said he thought he played well.
'Obviously, I didn't shoot it great but I can't really control that,' Scheierman said. 'I'm not trying to miss shots, you know?'
It was probably a healthy way of evaluating himself. Scheierman believed he made the right reads and defended at a high level. He saw beyond his shooting line.
To see the promise in his summer league performance, one needed to do that. While averaging 12.2 points per game over four appearances in Las Vegas, Scheierman shot an ugly 27.4 percent from the field, including 20.5 percent on 3-point attempts. He fired up nearly 10 3-point attempts per game, with nearly two-thirds of his shot attempts coming from behind the arc. He went 8 for 39 on those tries. Scheierman will likely need to shoot much better in the regular season to stick on the floor.
He still showed off impressive court vision, ranking near the top of the summer league leaderboard with 6.8 assists per game. For a wing his size, he can really see the floor and deliver tough passes with touch. He won't often be a primary playmaker during the regular season, but he created plenty of good looks for his teammates in that role at summer league.
It's raining threes early 🌧️ pic.twitter.com/dJFgbmml7D
— Boston Celtics (@celtics) July 13, 2025
With Tatum out indefinitely, Scheierman and Walsh could find themselves in competition for minutes when the regular season arrives. They were both good at summer league, if not spectacular.
(Photo of Baylor Scheierman and Jordan Walsh: Danielle Parhizkaran/The Boston Globe via Getty Images)