It’s easy to forget now but last summer the most important addition to the Celtics  wasn’t Shaquille O’Neal . That gets lost in the shuffle for obvious reasons, but that wasn’t the way it was intended when the Celtics signed Jermaine O’Neal  for two years and the full mid-level exception. That was the strongest free agent card Danny Ainge had to play over the summer and he used it all on the other O’Neal, who entered training camp with the expectation that he would be the starter.
But right from the start he was affected by various injuries including a knee problem that got worse to the point where it required surgery in late January. From that point on it was out of sight out of mind for Jermaine O’Neal and there were approximately 3,000 more, ‘When is Shaq coming back?’ question for every one about J.O.
As the Celtics head into the postseason they know that they have at least one of the O’Neals and it’s not Shaq, who watched Friday’s practice from the sidelines and remains a day-to-day proposition. “I just don’t want to take a chance,” Doc Rivers  said. “We’ll find out [Saturday].”
While Shaq has dominated the media’s attention, the players seem removed from the daily updates. “I really haven’t worried too much about it,” Paul Pierce  said. “When he’s ready, the Big Fella will be ready, so I don’t have to worry about it. The guys that are out there have to be ready and that’s it.”
So, Jermaine O’Neal who has played just 24 games this season and logged less than 500 minutes will likely jump center on Sunday when the Celtics open their first round playoff series with the Knicks. In a way, O’Neal has defied expectations with his late-season comeback, but only because there were none when he returned from surgery in late March.
“I didn’t know what to expect, so yeah, I didn’t have an expectation,” Rivers said last week.
Overall, O’Neal has been up and down in his eight games since returning. He had solid outings against Detroit and Philadelphia and then played 30 minutes without a rebound against the Bulls and Heat. On Monday he put up 15 points and 13 rebounds against the Wizards in 37 minutes on the court, which was twice as much as he had played in any other game.
The Washington game was important for O’Neal because he wanted to see how his body reacted to playing such a long stretch and he reported no swelling afterward, which was encouraging. O’Neal said that he is able to play as many minutes as the team needs. In reality he’s likely to see about 20 with Nenad Krstic  and Glen Davis  taking up the rest of the center minutes.
“It’s right on time. Sometimes it doesn’t come when you want it to come, but I feel like I’m right on schedule as far as understanding the positions and where I should be on the court,” O’Neal said. “Defensively, I’m great. Offensively, I’m still learning. Never in my career have I been in the position where I am now, which is not to worry too much about scoring and that’s a transition. No matter how you try to lock in on the situation it’s still difficult. The way our offense works, if you’re not in the right position you mess up somebody else’s position. All in all I feel great. Knee feels great.”
Any offense the Celtics get from O’Neal is a bonus, which he acknowledged has been the hardest thing for him to accept since he got here. They need him for his defense, rebounding and the threat of a shot-blocker. O’Neal has only blocked 30 shots this season, but that’s still half as many as the team’s leader in the category, Kevin Garnett , who has all of 57.
Yet even without a Mutumbo-like presence in the middle, the Celtics are still one of the NBA’s best  at protecting the rim. Only two teams — Orlando and Miami — allow fewer made shots per game at the rim than the Celtics and only two — Miami and Milwaukee — force a lower shooting percentage. Protecting the paint, getting back in transition and not allowing corner 3’s are the cornerstones of the Celtics defensive philosophy.
Like the other facets of the team, the Celtics interior defense has been up and down over the last six weeks. It cost them most noticeably against the Clippers (the DeAndre Jordan game), the Pacers when Roy Hibbert  went crazy and in last Sunday’s Heat debacle. When it goes wrong, it goes really wrong but more often than not, the Celtics’ struggles can be tied to other issues, mainly an offense that has been out of sync since early March.
Jermaine O’Neal isn’t the answer to the Celtics offensive problems, but he is likely their best defensive option at the position. It’s strangely fitting in this season where five different players have started at center that they would be back where they started.