I said it early in the thread, teams with young athletic bigs are going to give the Spurs trouble. Porzingas is pretty much THE young athletic big right now. A lot of people seem to have forgotten how much trouble Lopez has given Tim the last couple of seasons. To me, that was one of the first signs that Tim really was aging. There was a time when Tim would have just ripped him a new one. Instead, he went straight at Tim quite a lot, and made Tim put up some really bad shots on the other end. You notice that Tim played less than 21 minutes tonight, and that left the Spurs under-sized against this Knicks team.
There are always going to be teams that match up better against a particular team. If the Spurs meet a team like that in the playoffs, it will probably be a long series. Or a short series, with a lot of close games.