The Boston Celtics, by force, remade their frontcourt. That includes significant changes at the four and the five. Gone are Al Horford, Kristaps Porzingis, and Luke Kornet. They can turn to their wings and ask them to bump up a position. However, the more traditional options they will lean on are Neemias Queta, Luka Garza, Xavier Tillman Sr., and Chris Boucher.
It helps to have an option within that group who can comfortably operate as a standalone center or in double-big lineups. That individual is one of the team's returning players, Xavier Tillman Sr.
Still, he too must acclimate. He's adjusting to new teammates, a faster approach offensively, and a more aggressive one defensively. Tillman is also learning more about the dynamic nature of the four spot. It helps that he now has Chris Boucher as a teammate/muse.
Xavier Tillman Sr., told me he’s learning about the four spot from studying new teammate Chris Boucher.
“You’ve always gotta be active at the four spot. A lot of times, I always thought the four just kind of hung out in the corners and waited for catch-and-shoots, but he would… pic.twitter.com/ysLC5N8vo8
— Bobby Krivitsky (@BobbyKrivitsky) October 12, 2025
"That four spot is a little bit different," Tillman told Hardwood Houdini at shoot around before Sunday's preseason game against the Cleveland Cavaliers. "I like to watch Chris a lot because he's been playing the four for the majority of his career.
"So, just finding ways to be impactful, whether it's catch-and-shoot, or it's cutting, or it's offensive rebounding, figuring out where I can have an impact in that four spot as well."
What Tillman is learning from Boucher
Gaining an understanding of the various ways a player can take advantage of being at the four, rather than just parking themselves in the corner, is one matter. However, learning the nuances and how to maximize those methods is another.
When asked about what specifically Tillman is picking up from having Boucher in Boston, he conveyed the following to Hardwood Houdini.
"You've always got to be active at the four spot," replied Tillman. "A lot of times, I always thought the four just kind of hung out in the corners and waited for catch-and-shoots, but he would always look for his man to turn his head for a backdoor or fall asleep and then face cut him for a rebound or a cut. So, just learning different ways or different opportunities you have to get to the rim."
Now that Tillman's knee is healthy and he's slimmed down, shedding 12 pounds this offseason, he can capitalize on what he's learning from Boucher. Those corner crashes and basket cuts are suddenly a realistic avenue for him to produce points and extend possessions. It's another reason to enter the upcoming campaign optimistic about what he can contribute to a group taking a committee approach to providing the play the Celtics need up front.