The Spurs average 94.8 points per 48 minutes with Splitter on the court, while the opposition averages 95.0 points per 48 minutes ... meaning the Spurs have been outscored this year when Splitter is on the court.
Points Allowed Per 48 Minutes on the Court
Matt Bonner - 90.5
Richard Jefferson - 90.7
Tim Duncan - 91.5
Tony Parker - 92.9
TJ Ford - 94.7
Tiago Splitter - 95.0
Danny Green - 95.5
James Anderson - 95.9
Manu Ginobili - 96.3
Kawhi Leonard - 97.2
DeJuan Blair - 98.9
Gary Neal - 99.5
If you want to normalize the pace, as _JaG suggested, the Spurs average 105.4 points per 100 possessions when Splitter is on the court, while the opposition averages 106.7 points per 100 possessions when Splitter is off the court. When Splitter is on the bench, the Spurs average 112.2 points per 100 possessions, and the opposition averages 105.4 points per 100 possessions. So even normalizing pace, the Spurs are better on offense and defense with Splitter off the court.
The best arguments against these numbers are: 1. small sample size (although with last year's stats showing similar findings, this may be a hard argument to sell) 2. Splitter needs more playing time to figure out how he can positively impact the game.
Personally, even if I accept that the numbers aren't a fluke, that doesn't make me think less of Splitter. It just makes me think Splitter is even more in need of playing time so he can learn the NBA game. IMO, the worst thing Pop could do is to wait until the playoffs to throw Splitter into the fire ... like he did last year.