2025 Stats
W-L
2-4
ERA
4.24
WHIP
1.09
K
25
SV
3
Rest-of-Season Projections
2025 Fantasy Outlook
Slaten, a 2019 draft pick by the Rangers, was selected by the Mets during the Rule 5 Draft last offseason. The 26-year-old was subsequently traded to Boston and impressed his new club during Grapefruit League play, flashing upper-90's velocity. Unsurprisingly, he made the Red Sox Opening Day roster and remained with the team all year. Slaten was an immediate fixture in Boston's high-leverage hierarchy, mixing four pitches effectively to a 2.93 ERA, 1.01 WHIP and 58:9 K:BB across 55.1 frames. The rookie right-hander recorded 10 or more strikeouts on all four of his offerings, including 18 apiece on his four-seamer and sweeper. Elbow inflammation cost Slaten a month-and-a-half last summer, but it's exciting to think about what he could offer in a full season. Red Sox manager Alex Cora said in the past that he envisions Slaten as a potential long-term closer option and he certainly has the talent to emerge out of a save share with Liam Hendriks and Aroldis Chapman in 2025. Read Past Outlooks
Signed a one-year contract with the Red Sox in March of 2025.
Struggles continue
Slaten allowed two runs on two hits and one walk over a third of an inning in Wednesday's 5-4 loss to the Athletics.
Analysis
Slaten entered with Boston up a run and loaded the bases before getting the hook (10 pitches, four strikes). He was replaced by Steven Matz, who allowed a two of those inherited runners to score. Slaten was expected to be a bullpen asset when the Red Sox activated him from the injured list in late August, but the right-hander has been pummeled in six outings. Slaten has allowed seven runs on 12 hits and two walks over 5.1 innings.
Slaten entered with Boston up a run and loaded the bases before getting the hook (10 pitches, four strikes). He was replaced by Steven Matz, who allowed a two of those inherited runners to score. Slaten was expected to be a bullpen asset when the Red Sox activated him from the injured list in late August, but the right-hander has been pummeled in six outings. Slaten has allowed seven runs on 12 hits and two walks over 5.1 innings.
Pitching Stats
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2025 MLB Game Log
2025
2024
Minor League Game Log
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Pitching Appearances Breakdown
Average Pitch Count
14
Last 10 Games
12
Last 5 Games
12
How many pitches does Justin Slaten generally throw?
1-10
11-20
21-30
31-40
41-50
51-60
61-70
71-80
81-90
91-100
101-110
111-120
121+
What part of the game does Justin Slaten generally pitch?
1st
2nd
3rd
4th
5th
6th
7th
8th
9th
Extra
% Games Reaching Innings Threshold
% Games By Number of Innings Pitched
Left/Right Pitching Splits
Since 2023
-23%
BAA vs LHP
2025
-19%
BAA vs LHP
| BAA | K | BB | H | HR | ||||
|---|---|---|---|---|---|---|---|---|
| Since 2023vs Left | .188 | 41 | 15 | 28 | 3 | |||
| Since 2023vs Right | .245 | 42 | 4 | 46 | 4 | |||
| 2025vs Left | .189 | 10 | 7 | 10 | 1 | |||
| 2025vs Right | .233 | 15 | 3 | 17 | 2 | |||
| 2024vs Left | .188 | 31 | 8 | 18 | 2 | |||
| 2024vs Right | .252 | 27 | 1 | 29 | 2 | |||
| 2023vs Left | 0 | 0 | 0 | 0 | 0 | |||
| 2023vs Right | 0 | 0 | 0 | 0 | 0 | |||
| More Splits→ | View More Split Stats | |||||||
Home/Away Pitching Splits
Since 2023
-66%
ERA at Home
2025
-77%
ERA at Home
| ERA | WHIP | IP | K/9 | BB/9 | |||||
|---|---|---|---|---|---|---|---|---|---|
| Since 2023Home | 1.70 | 0.80 | 42.1 | 7.4 | 1.5 | ||||
| Since 2023Away | 4.98 | 1.26 | 47.0 | 9.2 | 2.3 | ||||
| 2025Home | 1.59 | 0.71 | 17.0 | 5.8 | 1.6 | ||||
| 2025Away | 6.88 | 1.47 | 17.0 | 7.4 | 3.7 | ||||
| 2024Home | 1.78 | 0.87 | 25.1 | 8.5 | 1.4 | ||||
| 2024Away | 3.90 | 1.13 | 30.0 | 10.2 | 1.5 | ||||
| 2023Home | 0 | 0 | 0 | 0 | 0 | ||||
| 2023Away | 0 | 0 | 0 | 0 | 0 | ||||
| More Splits→ | View More Split Stats | ||||||||
Stat Review
How does Justin Slaten 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
2.50K/9
6.6BB/9
2.6HR/9
0.8Fastball
96.5 mphERA
4.24WHIP
1.09BABIP
.253GB/FB
1.11Left On Base
54.9%Exit Velocity
81.9 mphBarrels/BBE
5.3%Spin Rate
2553 rpmBalls Hit 95+ MPH
19.4%Swinging Strike
13.7%Advanced Pitching Stats
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Defensive Stats
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Stats Vs Today's Lineup
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More Fantasy News
Shaky first outing off IL
Slaten allowed two hits and one walk while striking out one over a scoreless inning in Friday's 4-2 loss to the Pirates.
Analysis
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Back from 60-day IL
The Red Sox activated Slaten (shoulder) from the 60-day injured list Thursday, Tim Healey of The Boston Globe reports.
Analysis
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Activation expected Thursday
Slaten (shoulder) is expected to be activated from the 60-day injured list ahead of Thursday's series finale in Baltimore, Christopher Smith of MassLive.com reports.
Analysis
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Activation imminent
Red Sox manager Alex Cora said Monday that Slaten (shoulder) probably won't require another rehab appearance before being activated from the 60-day injured list, Tim Healey of The Boston Globe reports.
Analysis
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Sent out on rehab assignment
Slaten (shoulder) will begin a rehab assignment with Triple-A Worcester on Tuesday, Ian Browne of MLB.com reports.
Analysis
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