Cubs remaining schedule 3 vs Pirates, 3 vs Braves, 3 @ Reds, 3 vs Marlins and then finishing 3 @ Red Sox. The Reds and Marlins series probably the easiest of the 15 remaining. If the Pirates can some how sweep the Cubs that puts them back into the playoff discussion. Its possible the Cubs completely miss the playoffs with that remaining schedule. The only positive the Cubs have is that the Dbacks and Padres play each other which helps the Cubs as only one of them can win.
The Pirates though if they can sweep the Cubs only have 3 vs the Brewers and then they play 3 vs Royals, 3 vs Cardinals and then 3 @ Tigers. The Pirates have an easy schedule after the Cubs and Brewers series. They would have to at least win the series against the Cubs and then win the series against the Brewers. Then go 7-2 to finish the season. A sweep of the Cubs and they gain 3 games on the Cubs.
The Padres also have an easy schedule left with 3 @ Giants, 4 @ Rockies, 3 vs Marlins, 3 @ Dodgers and then 3 vs Dbacks. Other than the Dodgers and Dbacks that is a fairly easy schedule for the Padres.
The Dbacks also have a little bit more difficult schedule than the Padres but not by much. I only say this as they have a the Rangers and Marlins who are still decent teams. Dbacks have 3 vs Rangers, 3 vs Marlins, 3 vs Yankees, 3 @ Rockies and then finish 3 @ Padres.
The final two wild cards could come down to the last week of the season. The Pirates have to take care of business this weekend against the Cubs to have a chance. It is still more likely that the Cubs make the playoffs but there is a small chance they don't and it could be the Dbacks or the Pirates with the final wild card spot.