Merrill Kelly

36-Year-Old PitcherSP

Arizona Diamondbacks

2025 Stats

W-L

3-1

ERA

4.06

WHIP

1.06

Rest-of-Season Projections

W-L

ERA

WHIP

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2025 Fantasy Outlook

Before an early shoulder injury sidelined Kelly from mid-April to August, the right-hander was headed for a second consecutive impressive season, posting a 2.19 ERA over four starts. He had less success (4.96 ERA) following his return, but most of the damage was in August, and Kelly was back on form in September. Kelly finished with a greater HR/9 and struck out fewer batters in 2024, but when a pitcher misses four months, one should resist making judgments based on ratios/results and instead focus on the injury, which altered his pitch mix. Kelly threw more cutters and changeups than four-seamers for the first time in his career; however, he pitched well when healthy in April and September, putting him on a path for a normal winter of preparation. The Diamondbacks have confidence that the 36-year-old will return to his 2023 iteration (3.29 ERA, 9.5 K/9) and picked up his option. Read Past Outlooks

RANKS

Rest of Season

Overall Rank

Dynasty

From Preseason

#295

ADP

League Majors

Bats R

Throws R

40 Man Yes

Height 6'2"

Weight 210

DOB 10/14/1988

Born Houston, TX

College Arizona State

Drafted 8th Rd 2010 TB

Ready to start Wednesday

PArizona Diamondbacks

May 5, 2025

Kelly (hamstring) is listed as the Diamondbacks' probable starter or Wednesday's game against the Mets in Arizona.

ANALYSIS
The Diamondbacks are already having Corbin Burnes (shoulder) skip his start during the three-game series versus the Mets, but the team won't have to make any further additions to the rotation with Kelly having bounced back well since exiting his most recent outing Friday in Philadelphia due to right hamstring cramping. He's now experienced leg cramps in two of his last three starts, but Kelly has pitched effectively in each of those occasions. He'll enter Wednesday's contest with a 4.06 ERA and 1.06 WHIP over 37.2 innings on the season.

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Pitching Stats

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2025

2024

2023

2022

2021

2020

2019

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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2020 MLB Game Log

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2019 MLB Game Log

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Minor League Game Log

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Pitching Appearances Breakdown

Average Pitch Count

Last 10 Games

Last 5 Games

How many pitches does Merrill Kelly 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+

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+

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 Merrill Kelly generally pitch?

1st

2nd

3rd

4th

5th

6th

7th

8th

9th

Extra

1st

2nd

3rd

4th

5th

6th

7th

8th

9th

Extra

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

-4%

BAA vs LHP

2025

-6%

BAA vs RHP

2024

-6%

BAA vs LHP

2023

-4%

BAA vs LHP

	BAA	Batters	K	BB	H	2B	3B	HR
Since 2023vs Left	.220	613	130	63	119	23	4	19
Since 2023vs Right	.228	562	147	37	119	31	0	17
2025vs Left	.205	92	17	9	17	6	0	2
2025vs Right	.193	61	10	3	11	2	0	3
2024vs Left	.234	160	23	16	33	6	1	6
2024vs Right	.250	140	40	3	34	10	0	5
2023vs Left	.218	361	90	38	69	11	3	11
2023vs Right	.226	361	97	31	74	19	0	9
More Splits→	View More Split Stats

Home/Away Pitching Splits

Since 2023

-28%

ERA at Home

2025

-51%

ERA at Home

2024

-8%

ERA on Road

2023

-36%

ERA at Home

	ERA	WHIP	IP	W	L	SV	K/9	BB/9	HR/9
Since 2023Home	3.01	1.06	149.2	9	6	0	8.8	3.1	1.1
Since 2023Away	4.20	1.29	139.1	11	4	0	8.5	3.1	1.2
2025Home	2.60	0.98	17.1	2	0	0	4.7	3.6	1.0
2025Away	5.31	1.13	20.1	1	1	0	8.0	2.2	1.3
2024Home	4.19	1.16	38.2	2	1	0	7.2	2.1	1.6
2024Away	3.86	1.17	35.0	3	0	0	8.2	2.6	1.0
2023Home	2.59	1.02	93.2	5	5	0	10.2	3.5	0.9
2023Away	4.07	1.38	84.0	7	3	0	8.7	3.5	1.2
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Stat Review

How does Merrill Kelly compare to other starting pitchers?

This section compares his stats with all starting pitcher seasons from the previous three seasons (minimum 120 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 120 IP). See here for more exit velocity/barrels stats plus an explanation of current limitations with that data set.

K/BB

2.25

K/9

6.5

BB/9

2.9

HR/9

1.2

Fastball

91.9 mph

ERA

4.06

WHIP

1.06

BABIP

.225

GB/FB

1.12

Left On Base

66.7%

Exit Velocity

83.1 mph

Barrels/BBE

6.0%

Spin Rate

2319 rpm

Balls Hit 95+ MPH

29.1%

Swinging Strike

8.7%

Advanced Pitching Stats

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Defensive Stats

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Stats Vs Today's Lineup

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Past Fantasy Outlooks

2024

2023

2022

2021

2020

2019

Kelly's ratios were nearly equivalent to his breakthrough 2022 season, but he took a different path to get there. Last season, Kelly fanned a career best 25.9 percent of batters he faced, but he also walked them at a 9.6 percent clip, the highest mark of his career. However, the 16.3 percent K-BB% was his best in a full season. Kelly didn't change his pitch mix much, other than throwing a slider a bit and it was effective. His changeup was offering chiefly driving the increase in strikeouts. Despite posting strong ratios in 2022, Kelly wasn't trusted since he didn't miss many bats. Fast forward a year and Kelly is no longer a secret after fanning well more than a batter an inning and enjoying a strong playoff run. He's likely going to be drafted around 100 picks earlier this season, which puts him in risky territory, since that assumes Kelly continues to punch out hitters at the same rate. Don't shy away from Kelly, but don't expect a repeat of last season's newfound dominance.

This past season may go down as a career year for Kelly, but that's not to say he's unworthy of consideration for 2023. It will just be tough for him to repeat that level of run prevention over 200 innings. When he's on, Kelly can keep hitters guessing with his diverse repertoire -- he throws his four-seamer, changeup, cutter, sinker and curveball all at least 13% of the time. The stuff has not translated to strikeouts since Kelly made the jump from the Korea Baseball Organization years ago (career 20.8 K%), but he limits walks and can induce manageable contact for the defense behind him. Now 34 years old, Kelly may be on the verge of some age-related decline. Add in that he was pitching over his skis last season and Kelly seems likely to be overlooked in many leagues. Be ready to cut bait if the performance craters, but Kelly is very much in the mix to stream in favorable matchups to begin the season.

Kelly defied the odds with a successful return following surgery to remedy Thoracic Outlet Syndrome. Successful is relative, meaning Kelly exhibited nearly identical skills to 2019, his last full, healthy campaign. However, those skills translate to a below average pitcher with a pedestrian strikeout rate, supported by a mediocre 9% swinging strike mark. Kelly throws five pitches with only his curve (12.5%) and changeup (17.5%) topping a double-digit swinging strike level, but combined he throws them about one-third of the time. A tweak in mix could miss more bats, but even if it manifested, the impact isn't worth chasing in Kelly's age-34 campaign. Sure, take a shot in draft and hold, but there are better options for a roster spot in standard formats.

Kelly had a decent return to stateside baseball in 2019 after a successful KBO career, and was having a rather nice start to 2020 until something did not feel right five starts into the season. Examinations revealed Thoracic Outlet Syndrome which required surgery in September. The track record of full recovery from the surgery is not great -- just ask Tyson Ross, Matt Harvey, Mike Foltynewicz and Alex Cobb among others. Yet, Arizona still picked up Kelly's $5.25 million option for 2021 believing that Kelly will make a full recovery and be a contributor in some capacity. You do not need to make any sort of investment in the pitcher until you see some positive results from his post-surgery self. A first-year return to a similar skill level is incredibly unlikely.

Kelly, who signed with Arizona last December following a four-year stint in the KBO, led the Diamondbacks with 183.1 innings in 2019, though he struggled with consistency, going 13-14 with a 4.42 ERA and 1.32 WHIP across 32 starts. Kelly allowed too much loud contact (9.5 Barrel% and 42.2 Hard%), which, coupled with his flyball tendencies, resulted in a 1.4 HR/9. He also showed noticeable home/away splits, performing much better at home -- likely due in part to Chase Field's humidor. The righty flashed an uptick in velocity in his first four starts in September, resulting in a 1.00 ERA and 9.3 K/9. His final start of the year was not so pretty, but it was a strong finish overall and that should have him pretty well locked into a rotation spot for 2020. Keep an eye on his velocity in spring training, because if Kelly maintains the increased velo, he could be a significant profit earner as a late-round pick.

Kelly signed with Arizona and will get a chance to win a spot in the starting rotation after three seasons playing in South Korea's top professional league. An eighth-round draft pick by Tampa Bay, he got as far as Triple-A, where he had a 2.76 ERA and 8.5 K/9 in 2014, before going overseas. Kelly thrived in the KBO with a 3.80 ERA in four seasons while leading the SK Wyverns to the 2017 championship. His 4.09 ERA from 2017 doesn't look great, but it ranked in the top 10 in a hitter-friendly league, and he had a 9.0 K/9 with outstanding control (2.1 BB/9). Kelly says his velocity improved while in South Korea to the low-90s from the high-80s while in Triple-A. He'll be trying to make a unique transition as few players have moved to Major League Baseball from the KOB, and he's also doing so without any major-league experience. He's a fantasy baseball wild card.

More Fantasy News

Cramping issues return Friday

PArizona Diamondbacks

Hamstring

May 3, 2025

Kelly was removed from his start in Friday's 3-2 loss to the Phillies after five innings due to cramping in his right hamstring, Steve Gilbert of MLB.com reports. He took a no-decision and allowed one earned run on four hits and no walks while striking out two batters before being lifted.

ANALYSIS
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Gives up two homers in no-decision

PArizona Diamondbacks

April 26, 2025

Kelly allowed two runs on four hits and a walk while striking out four over six innings in a no-decision versus Atlanta on Saturday.

ANALYSIS
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Ready to start Saturday

PArizona Diamondbacks

April 25, 2025

Kelly (leg) is listed as the Diamondbacks' scheduled starting pitcher for Saturday's game against Atlanta at Chase Field.

ANALYSIS
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Exits early Sunday

PArizona Diamondbacks

Leg

April 20, 2025

Kelly exited Sunday's contest against the Cubs in the bottom of the sixth inning due to right leg cramping.

ANALYSIS
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Fans nine in win

PArizona Diamondbacks

April 15, 2025

Kelly (3-1) allowed a run on three hits and a walk over six innings Tuesday, striking out nine and earning a win over the Marlins.

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Latest Fantasy Rumors

Could be dealt

PArizona Diamondbacks

November 17, 2024

According to Will Sammon and Patrick Mooney of The Athletic, Kelly could be a trade chip for the Diamondbacks this offseason.

ANALYSIS
Arizona is receiving trade interest in its starting pitchers, and Kelly is a logical option to be dealt since he's in the final year of his contract. The right-hander was limited to 13 starts in 2024 due to a shoulder injury and had a 4.03 ERA, 1.17 WHIP and 63:19 K:BB over 73.2 innings.

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