Starting Pitcher Notes (May 4): Tarik Skubal's injury timeline, Davis Martin's breakout game, Aaron Nola's bounce back, and Trevor McDonald
Corbin Young examines several starting pitchers and their underlying metrics from May 4.
After researching injuries for fantasy baseball, I realized there’s variance in the injury categories. There’s even a generic “elbow surgery” label, which can make it murky.
Detroit Tigers’ starting pitcher Tarik Skubal will undergo arthroscopic surgery to remove loose bodies. There have been 23 reports of arthroscopic elbow surgery, bone chips, and loose body/bodies in the injury database (2023-2026), including three instances about Lance McCullers Jr., who missed 2 seasons.
The tricky part with this data is that when a player’s injury lingers into the following season, some manual cleanup is needed.
Average days on IL with arthroscopic, bone spur, loose bodies:
2025: 362.5 days (McCullers Jr. injured since 2023)
2024: 118.8 days (removed McCullers Jr. from average)
2023: 196.2 days (removed McCullers Jr.)
Average days past the eligible return date with arthroscopic, bone spur, loose bodies:
2025: 27 (but would’ve been 368.5 with McCullers Jr.’s initial eligible to return date in 2023)
2024: 70 days (removed McCullers Jr.)
2023: 160 days
The visuals below show each season's injury data via FanGraphs from 2023 to 2026.
Davis Martin, SP, White Sox
Chicago White Sox starting pitcher Davis Martin set a career-high in strikeouts (10) and matched a career-best in whiffs (19) against the Angels on Monday. Martin threw 7 scoreless innings, with 22.4% swinging-strike rate and a 26% ball rate across an efficient 85 pitches. That’s better than Martin’s career ball rate (35%) and swinging-strike rate (10.8%).
🪙Martin threw his changeup 2 mph harder on Monday, leading to it losing an inch of downward movement. He seems to locate the changeup well, low and below the zone, generating whiffs and weak contact. That aligns with Martin’s changeup 115 Location+ being a career-best and leading his arsenal in command.
🛝Martin’s slider led his arsenal from a swinging-strike standpoint, eliciting a 69.2% swinging-strike rate (that’s not a typo). I’ve never seen this before, but Martin’s slider had a 0% zone rate and 85% chase rate on Monday, throwing the slider low and below with righties and lefties chasing the pitch low and toward his glove side.
Martin profiles as a command-over-stuff type starting pitcher. When Martin locates and commands his pitches well, this is the type of upside we can find.
Aaron Nola, SP, Phillies
This might be a make-or-break week for Philadelphia Phillies’ starting pitcher Aaron Nola. He projects for two starts, which started well, throwing 6 scoreless innings, with 5 hits, 0 walks, and 5 strikeouts against the Marlins on Monday.
Nola had a 9.6% swinging-strike rate and a 35% ball rate on Monday, compared to a 11.5% swinging-strike rate and 37% ball rate in 2026, similar to his career averages.
🪝Nola’s knuckle curve was cooking, generating a 21.9% swinging-strike rate. His knuckle curve was effective against both sides of the plate on Monday. For context, Nola’s knuckle curve elicits an 18.6% swinging-strike rate throughout his career, as his primary option against lefties and righties. Interestingly, Nola’s knuckle curve added 3 inches of drop and 2 inches of glove-side sweep on Monday.
⏩Nola’s four-seam has been blasted against lefties, allowing a .757 wOBA (.589 xwOBA) in 2026. That’s much higher than 2025 (.345 wOBA, .363 xwOBA) and 2024 (.284 wOBA, .298 xwOBA) via the four-seam against left-handed hitters. Unfortunately, Nola’s four-seam command hit career lows, with an 86 Location+ before Monday compared to a 101 Location+ throughout his career.
Theoretically, Nola’s skills suggest he should perform better than his actual outcomes. However, it doesn’t help that the Phillies’ defense ranks last in Defensive Runs Saved (DRS) and 27th in Outs Above Average (OAA) in 2026. That’s worse than his DRS (No. 22) and OAA (No. 12) from the 2025 season. We might want to sell high on Nola if the 2nd start of the week goes well.
Trevor McDonald, SP, Giants
San Francisco Giants’ starting pitcher Trevor McDonald was recalled to start against the Padres on Monday. McDonald threw a 7-inning quality start (2 H, 1 ER, 0 BB, 8 SO, 1 HR) across 81 efficient innings. He had a 12.3% swinging-strike rate and a 36% ball rate on Monday.
👉McDonald relied upon sinkers (62%) and sliders (38%) against right-handed hitters. He was using the sinker for called strikes (39%), first pitch strikes (83%), and a few whiffs (9.8% swinging-strike rate) against the Padres.
🛝The slider generated a 25% swinging-strike rate on Monday, though most of them came low and away from right-handed hitters. McDonald tends to throw sliders against righties more often, making it a valuable pitch.
The Giants seem to have a type:
Low arm angle
Sinkers, sliders, and curveballs
Arsenals that move horizontally more often
McDonald fits that mold while relying more on his command (108 Location+) than stuff (98 Stuff+).
As always, brilliant stuff!
Is there a path for McDonald to get more starts in SF? Or was this start likely just a spot, and back to the minors he goes?