Everyone but the Cardinals.
Here is a link from Will Leitch.
http://www.sportsonearth.com/article/153308824/cardinals-playoff-opponents-cubs-piratesChicago Cubs. So here's the nuclear scenario. Like the Cardinals, the Cubs are one of baseball's signature, jewel franchises, and the two teams, because of geography and because of history, will always be connected. Since the Cubs have last won the World Series, the Cardinals have won 11. St. Louis has ruled the National League Central (and before that, East) while the Cubs have commonly finished in the basement. The Cardinals swindled the Cubs out of Lou Brock. This has been, roughly, 100 years of total Cardinals dominance over the Cubs. But they have never, not once, met in the postseason. Which means that if the Cubs were to somehow beat the Cardinals in the NLDS, almost all of those 100 years of history would be erased. Cardinals fans could cite the championships, Ernie Broglio, Bruce Sutter, all of it, and it wouldn't matter, because all a Cubs fan would have to do is say, "the 2015 NLDS," and it would win all arguments. Losing to the Cubs in the playoffs is, to put it mildly, a Cardinals fan's nightmare. (As I joked to one of my Cubs fan friends the other day, "My favorite team is the Cardinals. My second favorite team is the Cubs not winning the World Series.") If the Cardinals were to beat the Cubs if they play in the NLDS this year, it would be just one more log on the Cardinals Rule campfire. But if they lost, Cubs fans would never, ever let it go, and they would be right to. The Cardinals don't want to lose anyone this postseason. But they really, really don't want to lose to the Cubs. Which is yet one more reason for the rest of America to get behind the Cubs this October.