First things first, let me say that Nenad Krstic's offense has been very good. For a guy who hasn't learned the system yet, he's played very well. I don't think anybody can criticize him much for what he's done on the offensive end of the floor, and that includes his offensive rebounding, which has been a very pleasant surprise.
However, I'm surprised by the number of fans who have said something along the lines of "even if Shaq or JO are hurt, we'll be fine because we have Krstic". I think statements like that really overrate Krstic's game, and underrate the importance of defense and rebounding.
Krstic is a VERY weak defensive rebounder. You know all the criticism that BBD has gotten about his rebounding? Well, Krstic is quite a bit worse on that end. He's grabbing 3.7 defensive rebounds per 36 minutes, an absolutely horrific number. That's 10th among guys who have played for us this year, and is well behind Paul Pierce (5.0 DRB per 36 minutes). It's only very slightly better than Delonte West and Marquis Daniels -- 3.5 and 3.4 DRB per 36, respectively -- and isn't far off from Rondo's 2.9 or Ray's 2.8. That's right: our starting center is closer to Ray Allen as a rebounder than he is to Paul Pierce (let alone KG or Perk).
It's true that Krstic is new here, but I wouldn't expect his defensive numbers to improve drastically; he's been a very poor defensive rebounder since the '08-'09 season, at least, and has really only had one decent half-season in his career in terms of rebounding. In other words, it's a major weakness.
Why does this matter? As I'm sure we all remember, failure to secure defensive rebounds was a big part of our loss in last year's Finals. We are a middle of the road team in terms of rebounding, and replacing Perk with Krstic hurts tremendously in that area. Additionally, relying too much on Krstic handcuffs Doc in terms of the lineups he can play; you can't effectively play Krstic at center with either BBD or Jeff Green at power forward, as both of those players are poor rebounders as well.
Similarly, Krstic's defense isn't great. Again, some of this will improve with familiarity, and Krstic isn't terrible on the defensive end. He's just not as good as Shaq, JO, or Perk defending guys 1-on-1, and he's not as good as JO or Perk defending the pick-and-roll or on help defense. He may reach the level of "adequate" on defense, but it will never be a strength. Part of the strength of our defense is that it allows perimeter players to release their man to our big men waiting in the paint. Krstic just isn't as imposing down there as JO, Shaq, or Perk.
This isn't a thread to "bash" Krstic. Like I said, I think he's been great on one end of the floor. However, I do think it's very important that we have either Shaq or JO back; their presence is going to be a very important piece of our championship puzzle. As Danny said in the Shaughnessy interview, "Now if Shaq and Jermaine [O'Neal] can't play we could be in trouble". I agree with that sentiment, and don't want to see people disappointed if Krstic doesn't live up to their perhaps unrealistic expectations.
