This season, the Chicago Cubs have struggled a little bit. Despite the fact that some analysts have pegged them as the team to beat in the National League, they are sitting third in the National League Central, two games behind the Milwaukee Brewers and a half game against the rival St. Louis Cardinals.

Yes, some of their star hitters are struggling. Anthony Rizzo is batting a paltry .203 and Jason Heyward is only batting .226. The only Cubs players that are batting over .300 are Kris Bryant and Albert Almora Jr. However, it’s not their hitting that is costing the team some wins; it’s the starting pitching.

Going into this season, the Cubs were boasting a hearty pitching rotation. Jon Lester, Kyle Hendricks and Jose Quintana were joined by Yu Darvish and Tyler Chatwood, leading some fans to think this was the deepest starting rotation in the National League. However, it’s been an achilles heel, as only Lester and Hendricks are living up to their potential.

It’s almost the end of May, and not a single Cubs starting pitcher has thrown over 56 innings for the year. In fact, only Lester and Hendricks have thrown over 50, with Quintana close behind at 48.1, Chatwood having 43 innings and Darvish only having 40. As a group, the Cubs starters have thrown 239 innings, while their relievers have thrown 164.2 innings.

That’s something that needs to be addressed, especially considering how the MLB postseason operates. October is now considered a battle of the bullpens, and the Cubs relievers have done a phenomenal job this year, but it’s something that can’t be sustained. If the bullpen is being used the way it is now, the Cubs relievers are going to be overused by the time October rolls around, and they won’t make it very far.

Outside of Lester, Hendricks and Quintana (although he’s incredibly inconsistent), the starters aren’t able to go past five innings. A perfect way to measure this is something called a quality start. A quality start is defined as a pitcher who throws at least six innings and gives up three earned runs or less. It’s important because a starting pitcher who amasses more quality starts gives his team a better chance to win as well as stops the bullpen from being overused.

Hendricks is dominant at this, as he has six quality starts. Lester and Quintana are next with four each, while Chatwood and Darvish only have three. No starter has more than nine games started. The most concerning is Darvish, as he signed a six-year, $126 million deal in the offseason.

So, despite being paid an average of $21 million a year, Darvish can’t get out of the fifth inning. In five of his eight starts, Darvish has been pulled after only getting 12-14, resulting in Cubs Manager Joe Madden having to use his bullpen to get anywhere from 13-15 outs, compared to Hendricks’ starts when the bullpen only needs to get on average 6-9 more outs.

As a whole, the group has another issue. They are walking an insane amount of batters, with only Hendricks having fewer than 21 walks. Darvish is walking an average of nearly three batters a game, Quintana is issuing nearly 2.5 free passes, Chatwood is giving over four batters a base, and Lester is giving just over two.

On the bright side, the previous starts by Darvish and Quintana were encouraging. Both starters received the win, completed six innings, allowed one earned run or less, and lowered their respective ERA’s significantly. The only issue was they both had three walks or more, but it was still an encouraging sign.

The issue moving forward is making sure more starts like above happen, instead of a glimpse of what they can do. This applies to Darvish especially, considering he is in the first year of his mega contract. Make no mistake though; if the Cubs starting rotation starts firing on all cylinders, and they have the potential to do so, the rest of the National League will be put on notice. They have the potential to match any rotation in Major League Baseball, except for possibly the Houston Astros.

Keep in mind that hot streaks are common in baseball. So it wouldn’t be terribly surprising to see this group reel off ten straight quality starts. The problem is getting there. However, if the past two starts from Quintana and Darvish are anything to consider, it’s a step in the right direction.

Hopefully as the weather continues to improve, the Cubs will as well. Make no mistake about it; the Cubs are still the team to beat in the National League, especially considering the Dodgers have flown off the rails and the Nationals are struggling to stay healthy.