That's a great question. I'm assuming they would hold it off until the end of the regular season to see if its needed. Assuming the Cardinals won the Central, this would only be a major scheduling issue if the Cubs finished 0.5 games behind the Pirates and clinched the season series. There's a small chance it would matter if the Cubs finished 0.5 games ahead of the Pirates but the Pirates won the season series, but that would involve the Cubs making up 3.5 games in 23 games, despite losing 5 of 7 to the Pirates. That would mean the Cubs would have to outplay Pittsburgh by 6.5 games over 16 games. So we're talking Cubs going 14-2 and the Pirates going 8-9 or something. So if the unlikely scenario occurred the Cubs would be stuck playing that Philly game on Monday, probably starting some guy like Dan Haren and hoping for the best, and then the WC game on Wednesday.