Chicago Cubs: Looking at the upside of recent rotation additions

The Chicago Cubs won’t be able to immediately replace what Yu Darvish brought to their starting rotation, but they have been active recently in adding depth options to complement what should be a passable rotation in 2021.

Recently added right-handed pitchers Trevor Williams and Kohl Stewart are both low-risk signings who bring a good bit of upside if they can remain healthy and get their footing this season. Whether it’s as a back-end starter or long relief/spot starter, there will be plenty of innings for both and a few reasons to be somewhat optimistic.

Chicago Cubs add Trevor Williams and Kohl Stewart to the pitching mix.

First, a look at Trevor Williams. Williams was designated for assignment by the Pittsburgh Pirates last November, electing free agency after a five-year run with the Pirates that saw the former second-round pick hampered by injuries and inconsistencies over the last two years.

Williams is coming off a 2020 season in which he recorded a 6.18 ERA, a career-high 8.3 percent walk rate, and an astronomical 2.44 HR/9 rate across 11 starts and 51 innings.

Despite being worth minus-0.4 Wins Above Replacement, Williams did strikeout a hair under 8/9 IP last year (career-high). He also saw a significant uptick in groundballs and had an expected ERA more than a full run lower (5.01) than his actual ERA.

His positive numbers still weren’t great by any means, but they did trend more towards the 2017-18 version of Trevor Williams that showed promise. In just over 320 innings, Williams was worth 5.2 fWAR with an ERA hovering around 3.50.

He remained healthy in 2020 and has managed to hold his fastball velocity over the last few seasons, despite injuries such as an oblique strain that hampered his 2019 campaign. Williams is also still young, entering his age-29 season, and his slider (second most used pitch) has the makings of a solid pitch.

The swings and misses have been there, but results have been a bit unlucky recently.

If the Chicago Cubs can unlock some of what Williams brought to the mound in 2017-18, his $2.5 million deal for 2021 brings good upside as the Cubs attempt to find arms that can eat innings next year.

The upside is also there for recent addition Kohl Stewart, maybe even more so. Despite opting out of the 2020 season and not pitching with the Baltimore Orioles after signing with them last winter (Type I diabetic), the Chicago Cubs signed Stewart to a major-league deal worth $700,000 for next season.

Stewart is a former fourth-overall pick of the Minnesota Twins with just 62 innings of MLB innings under his belt, but is a once highly-regarded prospect with some fun pitch movement numbers to look at.

If he can work his way back to the mound and the Cubs can figure out how to maximize his repertoire with multiple plus-grade pitches, they will have themselves a solid low-cost gem on their hands.

Stewart is largely a sinker/slider pitch-to-contact pitcher who won’t pile up the strikeouts, but he’s been highly effective at keeping the ball on the ground throughout his career and the Cubs have had some success in utilizing sinkerball pitchers as the league has trended more towards finding high-spin four-seamer guys who attack up in the zone.

FanGraphs gives Stewart’s fastball a 60 FV grade, and 55 FV grades to his slider and curveball, a pitch he can use effectively as a put-away offering. At just 26 years of age, there’s still plenty of time for Stewart to find himself at the major league level.

In their attempt to find arms who can help get through a 162-game schedule, the Chicago Cubs have found two low-cost, decent up-side arms in Trevor Williams and Kohl Stewart. The right tweaks and a bit of good luck could end up giving Chicago an under-the-radar small victory as they look to take control of the NL Central next year.