Kohl Stewart Will Start in Place of Trevor Williams (Appendicitis) Today

I love all the Cubs beat writers and do truly appreciate the hard work they put in for us … but I also think it’s really funny when they’re scooped on a roster move by the Cubs lineup announcement.

That’s what happened today, when we learned that Kohl Stewart would be the one replacing Trevor Williams (appendicitis) in the rotation and on the mound against the Padres this afternoon.

The #Cubs today placed RHP Trevor Williams on the 10-day IL (retroactive to May 28) with appendicitis and recalled RHP Kohl Stewart from @IowaCubs. pic.twitter.com/DmGe1QpJBB

— Chicago Cubs (@Cubs) May 31, 2021

Stewart, 26, had been on the same pitching schedule at Triple-A as Trevor Williams was in Chicago and was already on the 40-man roster, so this was a pretty easy direction for the Cubs. Plus, with his pedigree, age, and five years of remaining club control, the Cubs were going to want to see him up close and personal at some point anyway. So at least there’s that (unfortunately for him, his spot start is against one of the toughest teams in MLB, the Padres).

As for what to expect from Kohl Stewart today, you’re going to get about 80-85% of the sinker/slider foundation. Probably topping at about 95 mph, with the slider command probably the most important element to his success. He’ll mix in a curve, change and a FB with a bit of cut. https://t.co/nV6z31KDXN

— Cubs Prospects – Bryan Smith (@cubprospects) May 31, 2021

Stewart has made four starts so far this season, really turning things up over his last two: 12.0 IP, 4ER, 2BB, 11Ks. He was called up as the 27th man for a double-header earlier this season, but didn’t pitch and he also opted out of the 2020 season. So today will be his first big league innings in two years.

Here’s some more via Brett from when the Cubs first signed Stewart this offseason (and in case you missed it, we covered Trevor Williams appendectomy yesterday):

To that end, when I think of where to categorize Stewart as one of the Cubs’ pitchers going forward, I kinda feel like he’s more of an experienced prospect than anything else. He’s roughly in that same age range as the Cubs’ AAA starting options (26), he’s still got minor league options left, and, again, his big league experience is really limited (barely 60 innings total between 2018 and 2019).

The Cubs signed another AAA starting-ish pitching prospect, joining the Tyson Miller, Cory Abbott, Keegan Thompson, Justin Steele-type group. That’s pretty much the better conception of this one.

And even from there, it’s more a scouting/transformation play than grabbing a guy you have high confidence in his ability to contribute, because the reality is that Stewart hasn’t actually even been all that productive at AAA or AA in recent years:

So you see the results there, including atrocious strikeout and walk rates, even in the minors, and you’re like … how is this guy getting a big league deal and being viewed as a prospect type who might still have upside?

Well, again, it’s because scouts have liked Stewart from his young days, which made him the 4th overall pick in 2013 draft, and saw him befuddle batters with weak contact in the lower minors even when he was a teenager.

Sometimes a guy has all the things you look for and just doesn’t put it all together in the results department. But if you get a chance to get the bones into a new organization and maybe put your own stamp on the development? When the upside is what the scouts can all see? Sure, it’s easily worth taking a relatively low-cost chance. You’re talking about a guy who has used SIX pitches in the big leagues already – it’s not at all hard to imagine playing with that pitch mix, tightening it up, and improving just one or two pitches, and suddenly you have something.

Consider some data points that Brendan Miller got into over at Cubs Insider: Stewart’s curveball moves more than 93% of all curveballs, and his changeup drops more than 90% of other changeups. The curveball also put up 79th percentile spin in 2019, per Statcast. And his slider has actually been his most valuable pitch in the big leagues, with a value per 100 pitches that would actually place it among the top 20 starters in baseball if he’d thrown enough to qualify. He netted whiffs on it 1/3 of the time he threw it.