After discussing the back up point guard situation, it became clear that not a lot of people agreed with the vision of Gregg Popovich of Neal as the answer. We all know Pop knows best and that he won't follow any advice we give him, but it's nevertheless interesting to see where everyone's thoughts are on rotation issues. The time, we'll focus on the big men.
With Tiago Splitter joining the starting lineup and DeJuan Blair seemingly out of the rotation, the likely possibilities as back up bigs seem to be Matt Bonner and Boris Diaw. It's virtually impossible to see Pop altering the starting lineup now--not when it's one of the best five man units in the league. Diaw seems to have the third big role locked up so all that is missing is a fourth big. But we'll get back to that. First let's look at the individual performances of all the Spurs F/Cs, starting with the least used.
Baynes has the potential to be a contributor as soon as next season but the Spurs have 15 players under contract, which means two guys have to be inactive and that will likely be Joseph and Baynes.
There have been trade rumors about DeJuan since last season but he is still with the team and as a change of pace fifth big he's probably one of the best in the league. It's been no secret Blair plays better with Duncan but after a good start of the season he simply couldn't hold on to the starting position. Considering Pop never trusted him in the playoffs, it was actually a good thing that he faded out of the rotation during the regular season despite his per minute stats being close to or better than his career averages on most categories. By now everybody is aware of DeJuan's strengths and weaknesses so I won't rehash them here but it still seems the team does better with DeJuan having a smaller role, and his energy off the bench could help change the tide on a uphill game.
Bonner has seen his role reduced, not unlike Blair, in a move that seems to have the playoffs in mind. It was probably a good decision by Pop but it has clearly affected his individual numbers. Bonner is having one of his worst statistical years and not even plus/minus seems to be saving him. He still does what he is supposed to do well, as his 42% from three is not far from his career percentage but he is below or near career lows in most other categories. He is still effective in certain lineups, usually alongside Tiago Splitter, but he seems to have earned the demotion with his play. As a situational player he has value but it seems Pop has decided to not rely on Bonner as much as he has in the past.
Diaw went from starter last season to first big off the bench this year and has slowly gotten better as the season progressed after a slow start, especially on defense. The last ten games the team has allowed a stellar 96.2 points per 100 possessions with BoBo on the court and the offense has done ten points better with him playing, resulting in a fantastic 17.4 net rating. Unfortunately, the rebounding woes still exist, as the team does consistently worse on the boards when Diaw plays, in large part due to Diaw posting rebounding percentages that would be mediocre even for a small forward.
He makes up for it by being a versatile two way player that can cover most power forwards and dish out assists or shoot on offense. He's still too tentative when it comes to pulling the trigger and that could hurt the Spurs on the playoffs but we've seen him step up his scoring in certain games, so we know he's capable of being a threat. While the Diaw-Splitter pair has been doing better, Boris still needs Tim Duncan to help with defensive rebounding. In lineups in which he is paired with either Bonner or Blair the team suffers so expect Diaw to play the majority of time with Duncan and Splitter in the playoffs, despite Pop's recent lineup experiments.
Splitter hasn't gotten better at virtually anything other than turnovers and free throw shooting; he's actually doing worst in most other categories, per 36 minutes. But while his individual numbers might have gotten worse with him starting and sharing the court with Duncan, the team seems to thrive with him in the starting lineup. With Splitter on the court the Spurs limit both the amount of attempts and percentage of makes close to the rim as well as opponent free throw attempts. The interior defense is unsurprisingly better with Splitter playing.
Despite not having the most diversified offensive game, Tiago also contributes on that side of the ball. Splitter does a few things on offense but he does them exceedingly well and that's enough for a team that has great playmakers and shooters surrounding him. But perhaps the most important aspect of Splitter's contributions is that he can share the court with Diaw and Bonner without the team suffering a steep decline, making him the only versatile big not named Tim Duncan in the roster when it comes to lineups.
There's not much to say about Tim Duncan that hasn't been said already. Duncan is still an elite big and the biggest reason the Spurs are experiencing a defensive renaissance. Duncan has a huge effect on opponent shots at the rim, with the Spurs allowing 5% less shots at the rim with him on the court on an almost 10% worse field goal percentage, probably thanks to Tim having a career year at blocking shots. He's also key when it comes to defensive rebounding and is the team's only reliable pick and pop threat. He's definitely more of a jump shooter now but he can still score in the post or near the rim when called upon. You all know how important Big Fun is for the Spurs' title chances so I won't go over it.
Finally, we have Stephen Jackson who is obviously not a traditional big but can cover as a small ball four. Now, if we go by regular season performance, Jackson should be out of the rotation. He has been one of the worse Spurs in pretty much every metric and has not been a part of one-big lineups enough to provide an idea of how good he might be at that position. But it's almost a certainty the injuries and personal problems have played a part on his poor performance and Jackson seems to dig deep and produce in the post season. In spurts, the Spurs could theoretically cause other teams some trouble if Jackson hits outside shot against bigs and posts up other small forwards when opponents adjust.
Pop seems to be leaning towards a three big rotation of Duncan, Splitter and Diaw with Bonner filling in when needed. Considering lineups that include Blair have not performed well in an admittedly small sample size, it seems the best possible rotation. I have serious reservations about the Bonner-Diaw pairing but it shouldn't be hard to figure out a way to keep either Duncan or Splitter on the court at all times. A few West teams like going small so the Spurs will be forced to match them with Jackson for a few minutes but I'd be hesitant about playing him more than it's demanded.
I don't see Pop making big changes at this point in the season and I'm personally OK with it. The West playoff teams either have big lineups (Clippers, Grizzlies, Warriors, Jazz) that the Spurs should be able to contain or, like I mentioned, like going small and dictate what lineup their opponents have to use (OKC, Nuggets, Rockets). I don't see either scenario resulting in a significant disadvantage for the Spurs, mostly due to the emergence of Leonard and Splitter as reliable contributors.
Stats via NBA.com/Stats. They don't include last night's game against the Suns.