Splitter might be able to win a one-on-one post up against a smaller player, but when you add help defenders to the mix he has never been able to get it done. Everyone crashes and Splitter can't pass out of the post after he starts his move or finish through weakside help. He's good when he catches moving to the basket, but the Spurs are better off running their normal offense against an Ibaka-less defense than trying to feed Splitter in the post no matter who is covering him.
Layups are back in play. If we can set good screens without getting fouls called, there should be some open runs to the basket. That will either force their perimeter defenders to sag off the shooters or get layups against Perkins/Adams/Collison, all of whom commit a ton of fouls per minute.
If OKC goes small, I would rotate Duncan and Splitter so that they can both go all out defensively every minute they are on the court and foul trouble is not a factor for the rim protector. I would definitely try a big lineup from time to time to see how it goes, but before the series starts I don't want Splitter or Duncan stuck trying to cover the perimeter, especially since we need to reserve the worst perimeter offensive player for Parker to cover for the sake of rest.
I'm really hoping the Spurs can play Patty a lot of minutes. I read some Blazers boards and saw a number of comments about how hard he made Lillard work. The Spurs will win a battle of attrition, and so much the better if Mills can match up with Jackson.