The problem for the Cubs isn't just that they're 8 games back, it's that they're tied with one team, have two in front, and likely no wild card spot to compete for. If the Brewers fall on their face, then that means the Reds won't have fallen on theirs. Cubs need the Brewers and Reds to collapse, and also to match the Cardinals. Any one of those on its own is not unreasonable, but all 3 at once? ....and they also need all of that to basically start to happen within the next two weeks. Yeah, the Cubs could win a few over the next week and climb a bit, but I'm not sure they're going to get definitive enough indicators to make any decision other than the one to sell in the short time left before the deadline.