The Boston Celtics didn’t make many midseason moves during their 2023-24 run to a championship, but one of their few additions was trading for Xavier Tillman Sr. from the Grizzlies, adding some more depth and versatility to their frontcourt rotation.
Going from the Grizzlies to the Celtics represented a stark change of scenery for Tillman. He left a young and hungry Memphis team that previously ascended to the top of the West, but were mired in a disastrous season filled with injuries. He arrived in Boston to a veteran team that had already cemented its place as one of the best and had one singular goal: win a title. On the outside, one would think that would bring more tension and more pressure, compared to the freedom of playing on a young team still trying to shock the world.
However, what was noticeable to Tillman was how the approach and vibe in Boston wasn’t what he anticipated, and is representative of how the team finally attained the NBA’s ultimate prize. His introduction into how different the mindset was in Boston came on his first call with head coach Joe Mazzulla, as Tillman learned quickly why Mazzulla is as unique a figure as there is in NBA coaching.
“The first thing he said to me on the phone was, you know, ‘Don’t be weird.’ And I didn’t know what that meant, so I had to check myself, like, ‘Okay, how would I be weird?'” Tillman recalled. “And for me, a lot of times I take myself so serious — like, I take basketball so seriously — that was the first thing that my mind went to. Like, okay, let me kind of relax into the situation, versus coming here like, ‘Alright, y’all, I’m ready to win this championship. Let me do X, Y, and Z.’ And I think that he noticed it right away, and noticed, ‘Hey, man, it’s alright to have fun.’ And he’s really good about having a balance of both. He’s good about picking on guys in the right way to get them to feel more comfortable and know that, you know, it’s just work. It’s just a game. This has nothing to do with your real life. And he’s really good at separating work-life balance, for sure.”
Once in Boston, Tillman saw his role shrink a bit from when he was in Memphis, going from over 20 minutes per game to just shy of 14. But he felt more comfort and could play more freely thanks to how defined everyone’s roles were with the Celtics. The buy-in from the entire Celtics team to chasing that ultimate goal of a championship, from the top stars down through the tight-knit bench unit, meant that Boston didn’t have the same internal battles over minutes and roles that other teams have.
“To be honest with you, it was actually pretty refreshing,” Tillman said of Boston’s approach to the rotation. “I felt like early on in my career, my whole mantra was trying to do whatever I can to beat the next guy so I can start eventually and keep ascending in my career. And when I got here and realized that, like, the goal is not ascension, the goal is championships. The goal is to perfect the role that you have, so for me, it’s on-ball defense, it’s help-side defense, it’s rebounding, it’s screening, and then it’s spacing and hitting threes. I feel like they told me off the rip, like, just how you mentioned, this is a matchup-based team. It’s not, ‘Hey X, if you play fantastic, you’re gonna be stuck in this line up and da-da-da.’ They’re like, no, it’s a matchup-based thing.
“Now, do we want you to play well? Absolutely, because you want to play well, too. But it was pretty refreshing to hear that no matter how bad or how good you kind of play, this is your role. So don’t really worry too much about it. Just come in each and every day, put in your work in the weight room and on the court, and live with all the results.”
After seeing how that approach resulted in a dominant run to a championship, Tillman was happy to sign back on for two more years in Boston, to continue working on perfecting that role. This summer, that meant getting more comfortable getting up shots from deep, which has shown up this preseason as Tillman went 6-for-11 on threes in his four appearances. As he explained, he didn’t do much work on his form, but had to get his reps up to get comfortable shooting at the volume the Celtics demand. Unable to do anything on the move on the court following an offseason procedure to address swelling in his knee that impacted him last year, he spent a lot of time with assistant coach DJ MacLeay (aka D Mac) working on knocking down catch-and-shoot opportunities so that he’s comfortable putting them up in the game.
As Tillman admits, the mental side is still a work in progress when it comes to shooting as much as the Celtics like. He is a “big man at heart” who likes paint touches, layups, and wide open shots, while also thinking of himself as a facilitator, always looking to move the ball along. However, there are times where it’s his job on a play to shoot the ball, and the staff’s concern isn’t whether he makes each one, but that he takes the shots he’s supposed to in the offense. That’s an adjustment, but it’s one that he is really enjoying embracing.
“I think the thought process is on execution versus, like, perfection,” Tillman said. “And when I say execution, we’re running plays to get open shots. We run our sets, we run our pick-and-roll schemes to get open shots. And obviously the goal is to make it, everybody knows that, but the true goal for us that coach really harps on is just taking the right one, versus us passing up on it because we think there’s a better one or something like that. He’ll be like, listen, I’m putting people in positions for a reason. That’s a shot that I know you can make. I’ve seen you work out. I’ve seen you put in the time. Like, this is a shot we need you to take if we want to take the next step, and if you want to take the next step in your development as well. So you know, the confidence that coach gives me is pretty cool, because he’s not really results based at all. He’s more execution of, hey, we set this play up so you can get the shot, so you have to let it go. Like, I don’t really care what happens, but it just helps the overall landscape of the game and keeps the defense honest.”
There’s still the desire to make as many as possible, but he’s starting to understand that if he takes those open shots or designed shots regularly, it forces the defense to respect that he’ll shoot and can open things up for others. There are plenty of teams that preach process, but not every staff is willing to follow through on what that requires. For players to buy-in, they can’t be worried about whether minutes will get taken away during a cold spell. Few teams afford players that luxury, which is largely because the Celtics’ floor is so high they don’t have to be as reactionary.
At the same time, committing to that approach also helps to yield better results. As Tillman explains, players who feel more free on the court, without that lingering concern about what their performance means for their future, tend to perform better.
“When you can go into a game and think that my minutes are not dictated on if I make shots or miss shots, you play extremely free. And inevitably, you probably will end up making more shots than you miss, because you’re not overthinking things to try to be perfect,” Tillman said. “You’re just playing, and I think that has been the mantra that Joe’s set for the team this season, and even when I got here, just kind of like, I want you guys to hoop, I don’t want you to overthink. I want you to be adaptable to whatever the defense gives us, and we make the reads based off that. If there’s people put in positions that we all feel isn’t right, then we’ll make some adjustments, but for the majority, he’s like, I’m gonna put everybody in a position that I feel you know is best for the team.”
While the offense is where Tillman has to put the most work in to fully feel that comfort, he’s been right at home on the defensive end since arriving in Boston. His versatility on that end adds another weapon for Mazzulla to deploy off of the bench, and allows the Celtics to attack opponents with more pressure and switching with his ability to guard quicker wings as well as stronger bigs. Tillman notes that the defensive talent level across the board in Boston makes it so easy to go out there and execute, because playing defense is much simpler when there isn’t a guy (or even worse, multiple guys) to hide and cover for. When there’s no clear weak link to attack, you can be more aggressive and make quicker decisions on switching, blitzing, and helping, knowing that you won’t be giving the offense a clear advantage.
As the Celtics get set to start their title defense on Tuesday night against the Knicks, they’ll do so without Kristaps Porzingis for a still undetermined amount of time. Those are big shoes to fill, but even with the star out, what each of Boston’s bigs are being asked to do on the court doesn’t change. For Tillman, that still means focusing on defense, spacing the floor, screening, and rebounding, not trying to overextend himself to be like Porzingis, and instead trust the rest of his teammates to fill in the gaps.
“I feel like I’m fortunate enough to have bigs with me who all kind of fill different roles that KP fills. Because obviously, KP is a unicorn, right? He’s a guy who can catch lobs. He’s a guy who can block shots at the rim. He’s a guy who can iso and hit mid-ranges. He’s a guy who can space and hit pick-and-pop threes. He’s a unicorn to be able to do it all,” Tillman said. “And so for us, for myself, Luke [Kornet] and Nee [Neemias Queta], our focus is, okay, well we can each kind of make up a part of KP — other than his sick ability to draw fouls and stuff like that with his pump fakes and stuff, because he’s 7’2. The other parts of his game, like me spacing the floor, or for Nee blocking shots, or for Luke being able to catch it on all the pick and roll and then make a play, whether that’s an assist or that’s a layup for himself. I think that we can all play a part that KP plays to help the team. And it’s really cool to have those other guys with me, though. So like you said, there is no overextending.”
Finding comfort is hard to put a price on for a player. There’s always the temptation to want more, but as Tillman’s learned in Boston, there is also freedom in a defined role. That’s not to say you stop pushing yourself to grow, but you can focus your efforts on maximizing your strengths and minimizing weaknesses when you’re in a place that values what you bring to the table.
Tillman has found that in Boston, and he doesn’t have to look far to see what it looks like for a player to maximize their abilities in a similar (but larger) role to what he’s asked to do in Al Horford. Aside from Brook Lopez, few players have done a better job adapting to a changing NBA and continue to impact winning like Horford, who added the three-point shot in the middle of his career and reimagined himself on offense as a more perimeter oriented big man in the second half of it.
For Tillman, he’s keeping a close eye on Horford and taking cues on how he handles himself on and off the court. He admires the mentality and approach of Horford to shooting the ball, where he never dwells on the previous shot, make or miss. He sees the way Horford sets the tone with his effort, and also the way he allows himself to disconnect and strike a work-life balance when home with his family.
There are perhaps teams out there that could provide Tillman with more minutes or more of the ball, but very few could replace the feeling he gets in Boston of being embraced for what he does in the time he is on the floor. For that reason, he’s back with the Celtics and ready to play his role to the best of his ability when asked, understanding he’s on the kind of team players dream of playing on.
“If I can do my role to the best of my abilities, I will then be ‘special.’ But it takes the team in order to do it,” Tillman said. “My role is not the same as JT’s, my role is not the same as KP’s. And so for me, if I’m able to do the things that I said — the defense, the screening, the spacing the floor — that makes me special. I don’t have to be or play like JT in order to be special, I can be special in my role, and that’s something that Joe has told me from the rip. And it gave me a lot of confidence, because you want to feel valued, more importantly than anything, no matter if you’re working any type of job, you want to feel valued. You want to feel like you matter, and the effort that you’re putting in is actually significant.
“And you know, when you can get that from the coaches, from crashing and getting offensive rebounds, or getting Sam Hauser wide open for a catch-and-shoot three, or spacing and hitting my own catch-and-shoot three, it’s a really cool feeling. It’s a feeling that, as a player, you sort of chase.”
