The Chicago Cubs have been one of the hotter teams in the MLB ever since the All-Star break and has firmly put themselves in position to make the MLB playoffs. They currently occupy the second wild card sport in the NL, and still have a pretty solid fighter's chance at claiming the NL Central division. Still, they just opened up a three-game series with the division-leading Milwaukee Brewers, and were handled pretty easily by a score of 6-2 in Game One. The fatal flaw that will keep the Cubs from reaching the playoffs was on full display in the first game, as their starting pitching has been their weakest link ever since Marcus Stroman was placed on the IL. His return is uncertain for this year, and it has had the Cubs starting rotation in flux recently.

Ever since the All-Star break, the Cubs have had arguably the best offense in baseball. They have been led by Cody Bellinger in a resurgent campaign that sees him in the NL MVP conversation, although it is highly unlikely that he would take the award over guys like Mookie Betts or Ronald Acuña Jr. Still, he has been one of the better hitters in baseball and a staple in the middle of the Cubs lineup. Guys like Seiya Suzuki, Jeimer Candelario, and Nico Hoerner have been swinging a hot bat as well, and although Dansby Swanson and Ian Happ have seen their scuffles as of late, both have been very solid hitters this year. Overall, the Cubs have a strong lineup from top to bottom, and their run production should be enough to propel them into the postseason.

In terms of pitching, the Cubs bullpen has been really strong in the second half. Closer Adbert Alzolay has cemented himself as one of the best closers in baseball this year, and Julian Merryweather and Mark Leiter Jr have been very consistent out of the pen. Nevertheless, ever since Marcus Stroman went down with injury and has seen a substantial stint on the IL, the weakness that is the Cubs starting rotation has been exposed. With uncertainty regarding if Stroman will even return this season, the Cubs have needed help filling their rotation, and although they have gotten good spot starts, every fourth or fifth day it seems they have to put up a crooked number on the scoreboard in order to win. The Cubs fatal flaw that will keep them from the MLB Playoffs will be the backend of their starting pitching rotation.

*Roster via ESPN

Starting Rotation

Justin Steele is quietly an NL Cy Young candidate for the Cubs this year. When Stroman was healthy, the start of the Cubs rotation was far from a flaw on this team. Even with Stroman being out, Steele has kept it up and continues to put out quality starts. After Steele, Javier Assad has come in and become a very reliable starter for them as well, consistency getting ground balls out of hitters and limiting extra base hits. Lastly, Kyle Hendricks hasn't had the best season for the Cubs, but he is a consistent veteran who should be able to be counted on towards the end of the season. However, this is where the rotation gets dicey, as they have two spots remaining that could go either way.

The last spot in the rotation was recently filled by Jordan Wicks in his MLB debut, and he was truly stellar. After giving up a home run to the first batter that he faced, he calmed down and pitched five strong innings, retiring his last fifteen batters. He had nine strikeouts in his debut, trying a franchise record for the most ever in a first starting appearance. Nevertheless, Wicks is a rookie and now just has one start under his belt, so having to rely on him in the stretch run is a very risky proposition. It would be likely to see him struggle at times, and as long as Stroman is still out, the Cubs are going to need to rely on him. Along with Wicks, the Cubs still have a fifth spot that needs filled, and there aren't many good options to look towards.

The reason Wicks was called up for his debut was because veteran Drew Smyly was really struggling. This resulted in Smyly being moved back into the bullpen, and it is unlikely that he will be returning to the starting rotation anytime soon. This last spot has been occupied by Jameson Taillon for most of the year, but simply put, he has not been that good. Taillon has pitched to a 5.62 ERA this season, and has really struggled over his last few starts. With Stroman indefinitely, the Cubs are just going to need to continue to throw Taillon out there. This could jeopardize the MLB playoffs for Chicago.

The hope is that Stroman will return at some point, and the Cubs should feel confident with Steele and Hendricks, as well as Assad with how good he has pitched recently. With that being said, the last two rotation spots are going to be given to Wicks or Taillon, and neither guy is a sure thing. This could result in the backend of the Cubs starting pitching rotation in becoming the fatal flaw that keeps them from the MLB playoffs.