2026 Stats
W-L
0-0
ERA
0.00
WHIP
0.00
K
0
SV
0
Rest-of-Season Projections
Signed a one-year contract with the Red Sox in March of 2026.
Sent to minor-league camp
The Red Sox optioned Kelly to minor-league camp Monday.
Analysis
Kelly was gunning for a spot on Boston's Opening Day roster after appearing in 28 major-league games for the club in 2025, finishing with a 4.58 ERA, 1.33 WHIP, three holds and a 35:12 K:BB across 35.1 innings. The 31-year-old right-hander will likely start out in Triple-A Worcester but would be in line for a call-up to the majors when the Red Sox need more depth out of the bullpen.
Kelly was gunning for a spot on Boston's Opening Day roster after appearing in 28 major-league games for the club in 2025, finishing with a 4.58 ERA, 1.33 WHIP, three holds and a 35:12 K:BB across 35.1 innings. The 31-year-old right-hander will likely start out in Triple-A Worcester but would be in line for a call-up to the majors when the Red Sox need more depth out of the bullpen.
Pitching Stats
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Left/Right Pitching Splits
Since 2024
-3%
BAA vs RHP
2026
No Stats
| BAA | K | BB | H | HR | |
|---|---|---|---|---|---|
| Since 2024vs Left | .232 | 37 | 21 | 35 | 7 |
| Since 2024vs Right | .226 | 59 | 18 | 44 | 6 |
| 2026vs Left | 0 | 0 | 0 | 0 | 0 |
| 2026vs Right | 0 | 0 | 0 | 0 | 0 |
| 2025vs Left | .217 | 11 | 6 | 13 | 0 |
| 2025vs Right | .297 | 24 | 6 | 22 | 3 |
| 2024vs Left | .242 | 26 | 15 | 22 | 7 |
| 2024vs Right | .182 | 35 | 12 | 22 | 3 |
Home/Away Pitching Splits
Since 2024
-12%
ERA on Road
2026
No Stats
| ERA | WHIP | IP | K/9 | BB/9 | |
|---|---|---|---|---|---|
| Since 2024Home | 4.47 | 1.49 | 48.1 | 8.8 | 4.8 |
| Since 2024Away | 3.92 | 1.05 | 43.2 | 10.1 | 2.7 |
| 2026Home | 0 | 0 | 0 | 0 | 0 |
| 2026Away | 0 | 0 | 0 | 0 | 0 |
| 2025Home | 4.96 | 1.59 | 16.1 | 7.2 | 5.0 |
| 2025Away | 4.26 | 1.11 | 19.0 | 10.4 | 1.4 |
| 2024Home | 4.22 | 1.44 | 32.0 | 9.6 | 4.8 |
| 2024Away | 3.65 | 1.01 | 24.2 | 9.9 | 3.6 |
Minor League Left/Right Pitching Splits (AAA)
Since 2024
-19%
BAA vs RHP
2026
No Stats
| BAA | K | BB | H | HR | |
|---|---|---|---|---|---|
| Since 2024vs Left | .194 | 22 | 13 | 13 | 3 |
| Since 2024vs Right | .157 | 21 | 15 | 11 | 0 |
| 2026vs Left | 0 | 0 | 0 | 0 | 0 |
| 2026vs Right | 0 | 0 | 0 | 0 | 0 |
| 2025vs Left | .245 | 15 | 7 | 12 | 3 |
| 2025vs Right | .220 | 15 | 13 | 11 | 0 |
| 2024vs Left | .056 | 7 | 6 | 1 | 0 |
| 2024vs Right | .000 | 6 | 2 | 0 | 0 |
Stat Review
How does Zack Kelly compare to other relievers?
This section compares his stats with all relief pitcher seasons from the previous three seasons (minimum 30 innings)*. The bar represents the player's percentile rank. For example, if the bar is halfway across, then the player falls into the 50th percentile for that stat and it would be considered average.
* Exit Velocity, Barrels/BBE %, Balls Hit 95+ MPH %, and Spin Rate are benchmarked against 2019 data (min 30 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.
* Exit Velocity, Barrels/BBE %, Balls Hit 95+ MPH %, and Spin Rate are benchmarked against 2019 data (min 30 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.
K/BB
2.92K/9
8.9BB/9
3.1HR/9
0.8Fastball
97.0 mphERA
4.58WHIP
1.33BABIP
.331GB/FB
1.27Left On Base
60.7%Exit Velocity
79.0 mphBarrels/BBE
3.1%Spin Rate
2338 rpmBalls Hit 95+ MPH
18.3%Swinging Strike
9.2%Advanced Pitching Stats
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Defensive Stats
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Stats Vs Today's Lineup
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2023 Fantasy Outlook
Kelly was a journeyman reliever earlier in his minor-league career. He gained fastball velocity during the off year in 2020 and came back racking up the strikeouts in 2021 and 2022, culminating with him fanning 72 batters (34.4 percent) in 49.2 innings at Triple-A Worcester before earning his MLB debut last season. In addition to his mid-90s fastball, Kelly sports a plus changeup that has similar movement characteristics to Devin Williams' famous "airbender" changeup. Kelly probably won't get saves as a rookie, but he could offer value in leagues where relievers who post good ratios and strikeouts are useful.
More Fantasy News
Receives September call-up
The Red Sox recalled Kelly from Triple-A Worcester on Monday, Tim Healey of The Boston Globe reports.
Analysis
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Reinstated, optioned to Worcester
The Red Sox reinstated Kelly (oblique) from the injured list Saturday and optioned him to Triple-A Worcester.
Analysis
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Set to begin rehab assignment
Kelly (oblique) will begin a rehab assignment with High-A Greenville on Thursday, Chris Cotillo of MassLive.com reports.
Analysis
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Placed on 15-day IL
Kelly (oblique) was placed on the 15-day injured list Friday, and his prior option to Triple-A Worcester was rescinded, Chris Cotillo of MassLive.com reports.
Analysis
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Sent back to Triple-A
The Red Sox optioned Kelly (oblique) to Triple-A Worcester on Monday.
Analysis
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Latest Fantasy Rumors
Should soon return to majors
Chris Cotillo of The Springfield Republican expects Kelly's stay at Triple-A Worcester to be a short one after being optioned Sunday.
Analysis
The right-hander has a 2.16 ERA and 1.26 WHIP across 16.2 innings for Boston this season, so it's only a matter of time before he's back in the big-league bullpen. Kelly likely won't be in the high-leverage mix for the Red Sox anytime soon, but it's not completely out of the question if the club trades away the likes of Kenley Jansen and Chris Martin, both of whom are pending free agents, this summer.
The right-hander has a 2.16 ERA and 1.26 WHIP across 16.2 innings for Boston this season, so it's only a matter of time before he's back in the big-league bullpen. Kelly likely won't be in the high-leverage mix for the Red Sox anytime soon, but it's not completely out of the question if the club trades away the likes of Kenley Jansen and Chris Martin, both of whom are pending free agents, this summer.