Jhonathan Diaz

Jhonathan Diaz

29-Year-Old PitcherRP
Seattle Mariners AAA
2026 Fantasy Outlook
There was no outlook written for Jhonathan Diaz in 2026. Check out the latest news below for more on his current fantasy value.
Signed a one-year contract with the Mariners in February of 2025.
Invited to spring training
PSeattle Mariners  AAA
February 11, 2026
Diaz was added to the Mariners' spring training roster as a non-roster invitee.
Analysis
Diaz was designated for assignment and outrighted to Triple-A in January, when the Mariners acquired Cooper Criswell. The left-hander will likely be a depth option for Seattle's bullpen this season, although he isn't guaranteed a spot on the Opening Day roster. He made just one big-league appearance in 2025.
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Pitching Stats
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2025 MLB Game Log
2025
2024
2023
2022
2021
2025 MLB Game Log
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2024 MLB Game Log
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2023 MLB Game Log
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2022 MLB Game Log
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2021 MLB Game Log
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Minor League Game Log
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Left/Right Pitching Splits
Since 2024
 
 
-11%
BAA vs LHP
2026
No Stats
2025
 
 
-100%
BAA vs RHP
2024
 
 
-27%
BAA vs LHP
BAA Batters K BB H 2B 3B HR
Since 2024vs Left .286 21 5 0 6 2 1 0
Since 2024vs Right .321 31 4 3 9 1 0 2
2026vs Left 0 0 0 0 0 0 0 0
2026vs Right 0 0 0 0 0 0 0 0
2025vs Left .500 2 0 0 1 0 0 0
2025vs Right .000 3 1 0 0 0 0 0
2024vs Left .263 19 5 0 5 2 1 0
2024vs Right .360 28 3 3 9 1 0 2
Home/Away Pitching Splits
Since 2024
 
 
-100%
ERA on Road
2026
No Stats
2025
No Stats
2024
 
 
-100%
ERA on Road
ERA WHIP IP W L SV K/9 BB/9 HR/9
Since 2024Home 4.50 1.70 10.0 0 0 0 6.3 2.7 1.8
Since 2024Away 0.00 1.00 1.0 0 1 0 18.0 0.0 0.0
2026Home 0 0 0 0 0 0 0 0 0
2026Away 0 0 0 0 0 0 0 0 0
2025Home 0.00 0.75 1.1 0 0 0 6.8 0.0 0.0
2025Away 0 0 0 0 0 0 0 0 0
2024Home 5.19 1.85 8.2 0 0 0 6.2 3.1 2.1
2024Away 0.00 1.00 1.0 0 1 0 18.0 0.0 0.0
Minor League Left/Right Pitching Splits (AAA)
Since 2024
 
 
-22%
BAA vs LHP
2026
 
 
-100%
BAA vs LHP
2025
 
 
-23%
BAA vs LHP
2024
 
 
-18%
BAA vs LHP
BAA Batters K BB H 2B 3B HR
Since 2024vs Left .232 289 67 21 61 9 1 6
Since 2024vs Right .298 835 171 56 225 50 2 21
2026vs Left .000 1 0 0 0 0 0 0
2026vs Right .500 13 2 1 6 1 0 0
2025vs Left .235 145 33 7 32 3 0 4
2025vs Right .306 441 83 17 127 28 0 14
2024vs Left .230 143 34 14 29 6 1 2
2024vs Right .280 381 86 38 92 21 2 7
Advanced Pitching Stats
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Defensive Stats
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Stats Vs Today's Lineup
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Recent RotoWire Articles Featuring Jhonathan Diaz See More
Recent RotoWire Articles Featuring Jhonathan Diaz See More
2023 Fantasy Outlook
Diaz spent most of 2022 in Triple-A, where he posted a 4.98 ERA, 1.36 WHIP and 46:20 K:BB over 47 innings. For a second straight season, he got a brief taste of the big-leagues, hurling 15.1 innings over four outings (three starts) and recording a 2.93 ERA. While that number looks good on the surface, Diaz gave up four walks in each of his first two appearances and logged a troubling 11:10 K:BB overall. Diaz doesn't throw hard -- he averaged 91.4 mph on his fastball last year during his time in the majors -- but he throws five different pitches, using all but his curveball at least 16% of the time last season. The slider was clearly his best pitch, as he threw it 44 times to big-league hitters during the campaign without giving up a hit while posting a 40.6% whiff rate on the offering. The southpaw ended the campaign on the 60-day IL with an undisclosed injury, and Los Angeles designated him for assignment in November before re-signing him to a minor-league contract the following month. He'll likely open the 2023 campaign back at Triple-A but should see some time in the majors at some point during the season.
More Fantasy News
Outrighted to Triple-A
PSeattle Mariners  AAA
January 28, 2026
The Mariners outrighted Diaz to Triple-A Tacoma on Wednesday.
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Booted from 40-man roster
PSeattle Mariners  AAA
January 23, 2026
The Mariners designated Diaz for assignment Friday, Adam Jude of The Seattle Times reports.
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Optioned to Tacoma
PSeattle Mariners  AAA
May 20, 2025
The Mariners optioned Diaz to Triple-A Tacoma on Tuesday.
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Rejoins big club
PSeattle Mariners  AAA
May 14, 2025
The Mariners recalled Diaz from Triple-A Tacoma on Wednesday.
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Dispatched to Triple-A
PSeattle Mariners  AAA
April 3, 2025
The Mariners optioned Diaz to Triple-A Tacoma on Wednesday.
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