The Chicago Cubs have reached a four-year extension with starter Kyle Hendricks, according to multiple sources:

Hendricks has been one of the more productive pitchers in the league since arriving in the bigs in 2014, posting a 52-33 record with a 3.07 ERA for his career thus far. Hendricks was also the ERA champion in 2016 (2.13), when he went 16-8 and finished third in NL CY Young voting.

According to FanGraphs, the 29-year-old ranks 16th in fWAR (10.1) among all pitchers between 2016-18, which is better than the likes of Zack Greinke and the richest free agent pitcher of this summer, Patrick Corbin.

Aside from a horrendous month of June, Hendricks was excellent in 2018. He posted a 2.84 ERA after the All-Star break, including a 1.79 ERA in six starts in the final month of the season. In fact, he has almost always been a second-half pitcher, posting a career 2.69 ERA compared to a 3.61 ERA in the first-half.

Cubs President of Baseball Operations Theo Epstein likely saw this as an essential move given the current layout of the starting rotation as well as the relative lack of pitching depth in the farm system.

Hendricks is the only starter on Chicago's staff under 30 years old. Jon Lester and Cole Hamels are both 35, while Yu Darvish will be 33 in August and has already had multiple procedures on his throwing elbow.

In a way, the extension is a way of acknowledging that Hendricks is the most important piece of the future of the rotation. And at an annual value of just over $14 million, the Cubs could be locking down a potential ace at a bargain price.