Former Michigan State Spartan Xavier Tillman Sr. was a spectator for Marcus Smart’s return to Boston just days prior to February’s trade deadline. Seeing the love, admiration, and obsession pour down from TD Garden’s sold out crowd with emotional cheers and chants throughout the evening was quite the sight to see.

A few days later, Tillman found himself repping green again and calling TD Garden home.

“We’ve always liked Xavier,” said Celtics President Brad Stevens. “He is obviously big and strong, moves his feet well laterally, so he’s been able to guard a number of people at a number of different positions well. Above that, he plays the game for the right reasons. He competes, he passes, thinks the game well. All the stuff that we’ve been fortunate with the guys we have, around our best players, that they’ve brought to the table. He knows how to play.”

Upon arrival, he talked about some pointers that Smart gave him about Boston in their time together with the Memphis Grizzlies in regards to his nine-year tenure.

“The main thing he told me is very similar to Memphis in terms of the grit and the grind, and how hard you have to work for the fans, you know, appreciation, stuff like that,” said Tillman. “Once you do show that you’re willing to hustle, they’re gonna love you after that, so, I love it.”

Tillman became a huge addition to provide stability for the Celtics’ centers and front court. It almost felt mandatory, with Kristaps Porzingis and Al Horford needing to be preserved ahead of the championship run due to age and health.

Joe Mazzulla would go to Tillman in crucial moments against other elite bigs, with his ability to anticipate and move his feet well to gain favorable positioning, deny ball-handlers on the drive, and be an intelligent defender. That first instance was in March against Nikola Jokic in Denver, along with playing alongside Al Horford in bigger lineups.

In the NBA Finals, Tillman hit a clutch corner three in front of the Dallas Mavericks’ bench and blocked Luka Doncic twice, helping secure Boston’s 3-0 lead on the road in the NBA Finals en route to their 18th championship.

With the Celtics having to diligently pace Horford and Porzingis unlikely to make his season debut until December and possibly later, Tillman, now more comfortable in Boston, is in line for a larger role, especially to begin the upcoming campaign. Perhaps that will even include opportunities for him to crack the starting lineup, for instance, on nights when Horford and Porzingis are both unavailable.

While Tillman’s return once seemed uncertain, bringing him back solidified the Celtics’ center rotation. His ability to operate effectively alongside another big creates more versatile lineup options for Joe Mazzulla to cycle through. And after stepping up in the playoffs, his second season in Boston, which looks like it will come with more opportunities, projects to see him make even more of an impact for the reigning NBA champions.