The Story of the 2025 Chicago Cubs Rotation, and Its Future

How it Started:
Or, I should say, where it ended. In 2024, the Cubs got at least 24 starts from five guys: Shota Imanaga, Justin Steele, Kyle Hendricks, Jameson Taillon, and Javier Assad. The hearsay suggesting there was little interest in re-signing Hendricks turned out to be true. As sad as it was to say goodbye to our last remaining 2016 champion, it was time. With Hendricks signing early in the offseason, the Cubs had one official rotation spot up for grabs. The Cubs signed Matthew Boyd to fill that one, but they never seemed seriously engaged with the top-tier free-agent starters (Corbin Burnes, Blake Snell and Max Fried), so they still had a spot to fill.

Outside of some Jesús Luzardo whisperings, the Cubs were only tenuously connected to bigger names via trade. With no trade falling into his lap, inevitably, Jed Hoyer did what he does best: lean on roster depth and sign some fringe free agents. Hayden Wesneski, who started 7 of his 28 games played in 2024, was traded to Houston. This left Jordan Wicks, who spent most of 2024 injured, as an “option.” Top prospect Cade Horton would be ready at some point, and the mystery box that is Ben Brown rounded out the organizational depth.

To all of those, the team merely added Colin Rea. Ok, that doesn’t sound great, but surely a mix of these guys could hold it down. As long as nobody missed significant time, this rotation looked good enough to compete in the division. Then, Javier Assad said, “Hold my beer.” An oblique issue flared up in spring training, guaranteeing that he would not be ready for the first few weeks of the season. Even with Assad set to miss a little time, the Cubs still had two left-handed horses at the top, and a dependable third option in Taillon. It was a setback, but this was not going to doom them early on. 

How It's Going:
The Opening Week rotation of Steele, Imanaga, Taillon, Boyd and Brown inspired confidence. Even with Steele going down in mid-April, Cubs starters pitched to a 3.50 ERA (ranked #6 in baseball) and a 12-5 record. Newcomers Rea (Steele's fill-in) and Boyd each held an ERA under 3.00 through April, which surely came as a surprise to fans. Sample size be damned, Cubs starters performed this well against the high-powered offenses of the Dodgers, Padres, Diamondbacks, and Phillies. If the bullpen didn’t blow seven saves over that span, they could have ended April with over 20 wins, instead of 18-13.

While the focus of this article is not the bullpen, it is worth noting that the bullpen in May had the lowest ERA in baseball, despite throwing the 7th most innings. Cubs closers converted eight of nine save opportunities. The rotation took a step back in May, but regression was certainly expected after Imanaga went down with a hamstring issue. As of June 8, the Cubs starters hold a 4.17 ERA. This is good for 19th in the league, which is a freefall from where they were at the end of May. There are two interesting data points here:

1. Starters issued 36 walks since May 1, the fewest in baseball; but
2. Opposing hitters smacked 31 long balls off Cubs starters, which is the 5th-most in baseball.

As for individual performances, Taillon is responsible for 11 of those 31 home runs, Rea has an ERA closer to 6.00 than 5.00, and Brown has not shown anything resembling consistency. In this span, the two best starters have been the rookie Horton and the aged veteran, Boyd. Boyd remains a nice surprise, with an ERA just over 3.00 and 40 strikeouts, but they need reinforcements outside of the eventual return by Imanaga—particularly since Horton is likely to have his workload managed and massaged a bit later in the year.

Where It Goes Next:
Hoping for a return to pre-May performance from the rotation is a pipe dream. Rea might get better, but Boyd might get worse. Taillon is what he is. Imanaga and Assad will eventually return. There will have to be help from without, though, as Hoyer has already acknowledged.

Merrill Kelly (from Arizona) and Zach Eflin (from Baltimore) rate among the high-floor, low-ceiling, relatively low-cost options already on the collective radar. Kelly is a 36-year-old who has been a model of consistency over his career. He currently has an ERA of 3.43, which would be the third-best on the Cubs behind Imanaga and Boyd. His strikeout rate would also be the third-highest amongst Cubs starters.

There will be skepticism regarding Kelly’s availability, as Arizona hoped to contend this year. A hot month for the team could take him off the trade block completely. Eflin might be an easier acquisition, as Baltimore sits 13 games out of the division and has already fired their manager in what is quickly becoming a lost season. The 31-year-old Eflin has an ERA of 4.47 through 8 starts in 2025. That ERA is inflated by one start where he allowed 8 earned runs, but he has given up 3 or fewer earned runs in 6 of his 8 starts. Eflin is also a pitch-to-contact starter who relies heavily on his sinker, which will help keep the ball in the yard.

Both Eflin and Kelly are upcoming free agents, and while both starters have pitched well, it should not cost a ton of prospect capital. Getting one (or both) of these starters will add some dependable depth to a rotation that desperately needs it. As for in-house options, the choices are few. Hitters are hitting nearly .300 against the former first-round pick, Wicks. According to mlb.com’s Top 30 Cubs prospects, only one pitcher not named Cade Horton is projected to debut in 2025, and that is righthander Brandon Birdsell. Currently shelved with a fairly severe shoulder problem, Birdsell may come in handy if the Cubs have a healthy lead in the division going into September, but he hasn't yet pitched even in the minors this year. Connor Noland leads the Iowa Cubs with 11 starts, where he has been solid but unspectacular. His 3.72 ERA and 1.20 WHIP make him the best starter on the Triple-A roster, since Horton was promoted. He is an option, but he does not have prospect pedigree and currently is not on the 40-man roster. Kenta Maeda was recently signed to a minor-league deal, but that's as much to help Iowa sell tickets and fill innings as out of any hope for big-league help.

It looks like the trade market is going to be the best way to add starting depth. With Steele out, the Cubs will need to add dependable arms. Hopefully, a trade for one of the starters mentioned above is the floor. There will be plenty suggesting that a Sandy Alcántara trade is necessary, but with how poorly his 2025 is going, that may be a gamble the front office is unwilling to take. It's going to be a seller's market, and half the league will be looking for pitching. The Cubs' rotation has exceeded the expectations of many so far, but it's a long season, and the injury bug is biting already. The goal has to be to add someone who will start games come October, and the sooner, the better.