Article: Make Or Break Players On The 2025 Blue Jays: Erik Swanson

[Bob Ritchie]

From family emergencies to injury to underperformance, everything went wrong for Erik Swanson in 2024. Can he turn it around?

On November 16, 2022, the Blue Jays traded Teoscar Hernández for Erik Swanson and prospect Adam Macko. In his debut season with the Blue Jays, Swanson made 69 appearances and ran a 2.97 ERA and 3.04 xERA (which analyzes a pitcher's exit velocities and launch angles to predict their expected ERA). His 32% whiff rate put him in the 79th percentile of all pitchers. In short, Swanson was an essential member of Toronto's 2023 bullpen. Unfortunately, 2024 went very differently. Swanson ran a 5.03 ERA, and his 5.18 xERA was even worse. His whiff rate fell all the way to the 28th percentile, and he put up -0.7 fWAR.

What Went Wrong in 2024?

Two spring training developments affected Swanson's preparation for the 2024 campaign, and very likely his performance. The first and most significant event concerned his four-year-old son, Toby. On February 25, Toby was hit by an SUV and airlifted to a hospital. He recuperated in a pediatric intensive care unit and was released from the hospital on March 7. Naturally, Swanson took some time away from camp to be with his family during the ordeal.

The second development was an injury. Soon after Swanson returned to camp, he suffered forearm stiffness. The injury and the absence limited Swanson to just two spring training appearances, in which he faced seven batters and threw 32 pitches. He started the season on the IL, making three rehab outings before his first appearance with the Blue Jays on April 17. Things didn't go well. Swanson ran a disastrous 9.77 ERA over his first 17 appearances, and the advanced stats didn't see much to like either. He ran a 7.34 FIP and a 55.8% hard-hit rate. The Blue Jays optioned Swanson to Buffalo on May 28. Things didn't get better. In 17 appearances with the Bisons, Swansons ERA and FIP were both up over 10.00. Nonetheless, he returned to an MLB mound on July 20. He ran a scary 4.95 FIP the rest of the way, but thanks to some serious luck, such as a 100% strand rate and a .185 BABIP, his ERA over that stretch was down to 2.55.

Swanson's profile also changed significantly in 2024. His splitter lost some of its sink and some of its arm-side run, but more importantly, he stopped hitting the zone with it, frequently locating the pitch off the plate to his arm side. It stopped performing well, and he utilized it significantly less. The most dramatic change was to his slider. In 2023, the pitch averaged nearly 10 inches of induced rise, but in 2024, the pitch had nearly no rise at all. It essentially functioned like a gyro slider.

The projection system ZiPS sees Swanson running a 3.91 ERA and  4.14 FIP in 2025, making him essentially a league-average reliever. However, there is a cautionary note. Swanson has had a setback at the current Spring Training. He experienced right elbow discomfort and will likely start the season on the IL.

What Can Go Right In 2025?

To answer the question above, we need to examine Swanson's 2024 more closely. The first positive sign was Swanson's improved xwOBA after his July 20 return from Buffalo. The chart below has the details. Before July 20, Swanson faced 70 batters. From the 71 plate appearances point on the chart, his rolling xwOBA moved steadily towards and ultimately below the MLB average xwOBA through to the end of the 2024 campaign. This trend is a positive sign for 2025.

Swanson's performance improved after his second Buffalo stint. Although his numbers were not as good as the ones he put up in 2022 and 2023, they were much better than the pre-July 20 period. What changed? The answer lies in the pitch data.

Pitch Data

Table 1 shows the critical metrics for Swanson's three-pitch arsenal: four-seam fastball, splitter, and slider. Notably, the average velocity and spin rates of the 2024 pitches were similar to the velocities and spin rates of the same pitch types in 2022 and 2023. Compared to the pre-July 20 timeframe, Swanson's fastball produced better xSLG and Whiff% results, and the xISO related to his slider was better after July 19. Swanson's split-finger fastball was a more effective pitch after July 19. The xSLG, xISO and Whiff% numbers were similar to his 2022 and 2023 results. Let's take a closer look at the splitter.

Why is my primary focus on the splitter? According to Baseball Savant's Run-Value metric, it has been Swanson's best pitch in recent years. His splitter's RV/100 (Run Value per 100 pitches) was +2.9 and +2.3 in 2023 and 2022, respectively. In 2024, the split-finger fastball's RV/100 was -2.9. On the good news front, Swanson's splitter generated a +2.5 RV/100 after July 19. For Swanson to succeed in 2025, he needs an effective splitter.

The Attack Zones

The Attack Zone chart below details Baseball Savant's zones in and around the plate. Except for the Shadow Zone, the other zones do not require an explanation. However, the Shadow Zone is worth examining.

The Shadow Zone is the width of two baseballs. I split the Shadow Zone into an inner zone and an outer zone; the inner zone resides within the strike zone, and the outer zone does not. I created the inner and outer zones to dive deeper into why Swanson's splitter was more effective after July 19. There are two reasons of note.

First, Swanson's split-finger fastball generated lower xSLG numbers in the Heart Zone and both sectors of the Shadow Zone. Second, after July 19, Swanson located a higher percentage of pitches into the outer rather than the inner section of the Shadow zone. Hence, batters connected on more pitches in an area (the outer zone) where it is more challenging to make good contact. Tables 2 and 3 show the particulars.

Other possible factors contributing to Swanson's better performance in the post-July 19 period include pitch sequencing and more reps. In summary, Swanson's improved performance after his return, mainly due to a more effective splitter and, to a lesser extent, the four-seam fastball, bodes well for 2025.

How Will This Impact the Blue Jays?

Among MLB reliever corps, Toronto's 2024 bullpen ranked near the bottom in many metrics. The Blue Jays' crew was 28th in WPA and 30th in FIP and fWAR. For Toronto to contend for a playoff spot in 2025, they will need better bullpen results. Toronto's signing of Jeff Hoffman and the re-signing of Yimi García should bolster the reliever squad. However, Toronto would benefit significantly from a return to form by Swanson.

Why? Because Swanson was an essential member of Toronto's 2023 bullpen. He was primarily a set-up man (74% of his outings started in the seventh and eighth inning), and he appeared in the ninth inning in 13 of his 69 (19%) appearances. If Swanson can return to his 2023 form, he would provide Manager John Schneider with another high-quality, late-game option in the bullpen. The 2025 Blue Jays undoubtedly count on Swanson's improved performance.

The Last Word

Swanson likely wants to put the 2024 season in the rearview mirror. However, his numbers improved after returning to Toronto for the balance of the 2024 season. In particular, his split-finger fastball, his most important pitch in recent years, was very effective after he departed Buffalo in July. On the assumption that Swanson's current injury woes will not materially affect his performance, Swanson should be a key member of Toronto's bullpen, as he was in 2023.

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[Jonn]

Feel like a few guys have jumped him on the depth chart. Should begin the year in low leverage and work his way back into an important roll. And that all depends if hes actually going to be healthy because the jury is very much out on that as well.

[Spanky99]

I was pumped to see him pitch this season after that 2nd half, hopefully this forearm issue again, isn't too serious. It's recurring so that's no bueno.

[ian]

Having his good splitter could be huge for the bp against lhh.