Four MLB Rookies Enjoying Underrated Seasons
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We’ve used this space recently to examine both the NL and AL Rookie of the Year races. Today, we’re highlighting four players who may be flying a bit more under the radar.
Spencer Schwellenbach, RHP, Braves
The last time a Braves rookie pitcher named Spencer burst onto the scene midseason, it worked out quite well.
While Strider is currently sidelined with a torn UCL, Schwellenbach has stepped up to help fill a huge void in Atlanta’s rotation.
Since his May 29 debut, the 24-year-old has recorded a 4.04 ERA with a 1.04 WHIP, a 3.19 xFIP and a 70:10 K:BB in 64.2 innings.
He’s been even better of late. Since the calendar flipped to July, Schwellenbach has a 2.45 ERA, a 0.79 WHIP, a 2.55 xFIP and an incredible 38:1 K:BB in 33 innings.
Here are his league-wide ranks since his first start of July:
For context, his 29.8 K-BB% barely trails Nick Pivetta for the MLB lead during this time. It’s also well ahead of fellow rookie Paul Skenes’ 22.2% mark over that span. While Skenes has the better K-BB% for the season and remains deserving of NL ROY honors, it’s impressive that Schwellenbach keeps getting better with more experience.
He recently became the first rookie in the modern era to strike out eight or more batters without allowing a walk in three straight starts.
As noted in our June 2024 Top 100 update, Schwellenbach has little recent experience as a pitcher. He focused on shortstop while at Nebraska, though he also displayed upper-90s velocity as the team’s closer. He needed Tommy John surgery after being drafted in 2021 and didn’t return until last season.
Although Schwellenbach’s lack of a track record could be concerning, it also speaks to his upside. He pitches for a well-regarded organization and throws six pitches at least 9% of the time. His fastball sits at 96 mph, and his slider has a 112 Stuff+. Additionally, Schwellenbach has the second-lowest ball percentage among all starters with at least 60 IP this year. It’s a formula that becomes hard to poke holes in the more one dives in.
Colton Cowser, OF, Orioles
Cowser’s rookie campaign is very encouraging overall. He leads all rookie position players in fWAR and homers while ranking fifth in wRC+ and third in RBI.
However, the “shape of his season” has been inconsistent. One’s impression of Cowser’s season could be impacted by when they decided to roster him in fantasy or dive into his stats. Here’s his wRC+ by month:
- March/April: 178
- May: 68
- June: 90
- July/August: 160
Only nine qualified hitters have a wRC+ of 160 or above this season, which means that for two individual months, Cowser has produced like a top-10 hitter in MLB.
Cowser’s issue isn’t a secret. His season-long strikeout rate is in the bottom 10th percentile, per Baseball Savant. His zone-contact rate is among the bottom 20 hitters in the league. There’s swing-and-miss to his game. What’s interesting is that it doesn’t stem from chasing outside the zone:
After being overly selective in his first taste of the majors last summer, Cowser is doing better at being aggressive inside the strike zone. He’s hitting the ball harder, too, as evidenced by an 88th-percentile hard-hit rate and a maxEV of 113.6 mph.
What hasn’t translated has been the mid-teens walk rates Cowser consistently put up in the minors. There’s been speculation that many of his takes are predetermined— a theory backed up by a chase rate that spikes with two strikes. Add in the aforementioned contact struggles, and it’s easy to see where Cowser’s streakiness comes from.
His defense keeps him in the lineup as a near-everyday player for Baltimore. DRS and UZR have viewed Cowser’s glove work as positive, but he shines in Statcast’s Outs Above Average, coming in at sixth among all outfielders.
How his bat finishes the season could determine his chances in a wide-open American League Rookie of the Year race. Entering Monday, he leads all rookies in fWAR. Cowser’s defense provides a strong floor, but what he does at the plate will determine his ceiling.
Nolan Schanuel, 1B, Angels
Schanuel was drafted on July 9, 2023 and debuted for the Angels on Aug. 18 after just 22 minor league games. Schanuel performed well in his first taste of pro ball, but it’s also fair to say he was fast-tracked, or rushed, to the big leagues.
Complicating matters was that the Angels did this with a first baseman who didn’t appear to have much power potential. His 25.6% hard-hit rate was viewed as a non-starter for a corner infielder without speed.
He has the inverse of Cowser’s situation, where his season-long 105 wRC+ is fine but not great.
However, if we zoom in on his stretch from June 25 through July 30, we’ll see that he hit .337/.452/.485 with identical 15.3% strikeout and walk rates. He still only hit three homers during this stretch, but his 168 wRC+ was among the top-20 hitters in baseball during it.
From the beginning of the season until June 24, Schanuel had a 37.6 Z-Oswing%. From June 25 through July 30, that was 48.2%. This means he’s doing a better job of chasing less outside the zone while still hunting strikes. It makes sense that a young player without much pro experience is getting better, and it has helped dramatically lower his grounder rate:
Cade Smith, RHP, Guardians
The 25-year-old Smith hasn’t only been one of the best rookies in MLB this season. He’s been one of the very best relievers overall:
When trying to better understand a pitcher in a smaller sample, it’s helpful to look at Stuff+, which shows Smith has three above-average pitches.
His most-used offering is his four-seamer, which is thrown primarily at the top of the zone. Smith leans on it roughly two-thirds of the time, which (combined with its dominance) has led to the single highest run value among all pitches in baseball, per Savant.
Smith also has a splitter that Stuff+ views as the second-best in MLB, only behind Fernando Cruz’s. Add a sweeper with the same whiff rate as his fastball and split-finger, and Smith’s arsenal is ideal from a modern-day analytical perspective.
Among relievers, only Jeff Hoffman of the Phillies had accrued more fWAR than Smith entering Monday. Smith is joined in the top 10 by fellow Guardians Emmanuel Clase (t-4th) and Hunter Gaddis (t-8th). Cleveland’s bullpen has, therefore, been the most valuable in baseball this season and is a huge reason why the club has the best record in MLB.
