The New York Knicks are in the NBA Finals, where they might meet a 7-foot-4 guard/center who spent time learning from monks over the summer. Assuming I’m not deep in a strange dream, the Celtics are weeks into an interesting offseason, so it’s a good time to answer some mailbag questions.Questions have been lightly edited for length and clarity.How off-base is the part of the fandom that blamed coach Joe Mazzulla for the Celtics “failure?” Let’s put it this way: if one or two more shots in Game 7 had gone down in a critical stretch, they would have been still playing (although the Knicks have been playing like mad, so I’m not sure they would have done any better). But seeing folks calling for coaching staff changes and even a head coach change makes me think that folks have an unrealistic view of what we could get if we were crazy enough to get rid of Joe. — David Y.The Celtics should not consider firing Joe Mazzulla for a second. He turned a “gap year” into a 56-win season — and that was the worst regular-season record of his head-coaching career. While his previous rosters were ready-made, this one required more teaching. The team overachieved this season partly because Mazzulla turned an inexperienced supporting cast into a strength. He deserves plenty of credit for the development of Boston’s young players. He created a system and mindset that carried the Celtics far beyond expectations. He was a worthy Coach of the Year award winner.That said, Mazzulla needs to alter his approach in the playoffs. He needs to be quicker to make major adjustments within a series. After he inserted Robert Williams III into the starting lineup in Game 6 of a second-round series in 2023, the Celtics sounded surprised it took Mazzulla so long to make that call. Kristaps Porziņģis hurt the Celtics during the 2025 playoffs, but Mazzulla kept the big man in the rotation instead of turning to the highly capable Luke Kornet. Nikola Vučević gave Boston very little late in the regular season, but Mazzulla still stuck with him through six games of the first round. It wasn’t until Game 7 that Mazzulla made his first big rotation adjustments of the series. He might have gone overboard when he did, giving three players their first playoff starts ever.The best playoff coaches are quick and decisive when they spot a necessary change. Mazzulla needs to prove he can recognize and follow through on the tweaks that turn a series. The Celtics have now lost stunning series upsets in three of his four seasons. Of course, under his guidance, they also crushed everyone on their way to the 2024 championship.The playoffs exposed parts of the Celtics roster. The team still should have found a way to win one of the final three games against the 76ers, especially considering two of those games were in Boston.Who’s your dream starting center, and what would it take to trade for them? — Jeff M.Giannis Antetokounmpo talk aside, what are the realistic options for building out a more playoff-ready big man rotation? Does Neemias Queta stay the starter in all scenarios? — Nick G.The Celtics’ frontcourt surpassed all expectations throughout the regular season, but the first round shone a light on that group’s flaws. The best bet for the offseason is that Celtics general manager Brad Stevens will pursue another center to either take Queta’s starting spot or serve as a worthy backup to him.One problem? The market for big men won’t be particularly robust. Assuming the Thunder hold onto Isaiah Hartenstein, who has a team option for next season, the most appealing free agents are likely Mitchell Robinson and Robert Williams. The Celtics will have the $15 million mid-level exception to pursue targets in July. Presumably, they would need to offer Robinson a long-term contract to have a chance of landing him. Williams, who has dealt with plenty of injury issues throughout his career, could potentially be available on a shorter-term deal.