Riley O'Brien

Position: Relief Pitcher

Bats: Right • Throws: Right

6-4, 180lb (193cm, 81kg)

Born: February 6, 1995 in Seattle, WA us

Draft: Drafted by the Tampa Bay Rays in the 8th round of the 2017 MLB June Amateur Draft from College of Idaho (Caldwell, ID).

Schools: College of Idaho (Caldwell, ID), Everett Community College (Everett, WA)

Rookie Status: Exceeded rookie limits during 2025 season

2026 Contract Status: Pre-Arb Eligible

Service Time (01/2026): 1.129 • Arb Eligible: 2028 • Free Agent: 2031

Full Name: Riley Chun-Young O'Brien

Instagram: @rileyyobrien

View Player Info from the B-R Bullpen

Relatives: Grandson of Johnny O'Brien; Greatnephew of Eddie O'Brien

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SUMMARY

2026

Career

WAR

0.4

1.4

ERA

3.72

3.61

36.1

94.2

WHIP

1.156

1.320

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Year	Age	AgeDif	Tm	Lg	Lev	Aff	W	L	W-L%	ERA	RA9	G	GS	GF	CG	SHO	SV	IP	H	R	ER	HR	BB	IBB	SO	HBP	BK	WP	BF	WHIP	H9	HR9	BB9	SO9	SO/W
2014	19	-0.5	Kelowna	WCL	Smr		0	0		0.00	0.00	1	0	1	0	0	0	0.1	1	0	0	0	0	0	0	0	0	0	2	3.000	27.0	0.0	0.0	0.0
2017	22	0.8	College of Idaho	CCC	NAIA		3	4	.429	2.15	3.36	20	6		0	0	4	67.0	50	25	16	0	23		81	6	0	6	281	1.090	6.7	0.0	3.1	10.9	3.52
2017	22	1.3	Princeton	APPY	Rk	TBR	1	0	1.000	2.20	2.20	11	10	0	0	0	0	41.0	28	10	10	1	17	0	40	4	0	3	159	1.098	6.1	0.2	3.7	8.8	2.35
2018	23		2 Teams	2 Lgs	A-A+	TBR	8	4	.667	2.75	3.26	25	13	3	1	1	0	88.1	59	32	27	4	42	1	103	2	0	9	357	1.143	6.0	0.4	4.3	10.5	2.45
2018	23	0.0	Charlotte	FLOR	A+	TBR	4	3	.571	3.60	4.05	10	8	0	1	1	0	40.0	36	18	16	1	21	1	37	0	0	4	172	1.425	8.1	0.2	4.7	8.3	1.76
2018	23	1.1	Bowling Green	MIDW	A	TBR	4	1	.800	2.05	2.61	15	5	3	0	0	0	48.1	23	14	11	3	21	0	66	2	0	5	185	0.910	4.3	0.6	3.9	12.3	3.14
2019	24		2 Teams	2 Lgs	AA-A+	TBR	7	6	.538	3.16	3.59	20	17	0	1	1	0	102.2	76	41	36	6	44	0	107	7	0	11	429	1.169	6.7	0.5	3.9	9.4	2.43
2019	24	-0.3	Montgomery	SOUL	AA	TBR	5	6	.455	3.93	4.33	14	11	0	1	1	0	68.2	56	33	30	4	29	0	72	6	0	8	297	1.238	7.3	0.5	3.8	9.4	2.48
2019	24	1.1	Charlotte	FLOR	A+	TBR	2	0	1.000	1.59	2.12	6	6	0	0	0	0	34.0	20	8	6	2	15	0	35	1	0	3	132	1.029	5.3	0.5	4.0	9.3	2.33

2021	26	-1.0	Louisville	AAAE	AAA	CIN	7	7	.500	4.55	4.71	23	22	0	0	0	0	112.2	93	59	57	16	55	1	121	10	0	7	490	1.314	7.4	1.3	4.4	9.7	2.20
2021	26	-2.9	CIN	NL	Maj	CIN	0	1	.000	13.50	13.50	1	1	0	0	0	0	1.1	2	2	2	2	3	0	2	0	0	0	9	3.750	13.5	13.5	20.3	13.5	0.67
2022	27		2 Teams	2 Lgs	AAA	SEA	1	3	.250	7.03	8.62	33	1	4	0	0	0	39.2	45	38	31	5	30	0	47	5	0	4	196	1.891	10.2	1.1	6.8	10.7	1.57
2022	27	-0.2	Tacoma	PCL	AAA	SEA	1	3	.250	7.12	8.84	32	1	4	0	0	0	36.2	43	36	29	4	29	0	43	5	0	3	184	1.964	10.6	1.0	7.1	10.6	1.48
2022	27	0.0	Louisville	IL	AAA	CIN	0	0		6.00	6.00	1	0	0	0	0	0	3.0	2	2	2	1	1	0	4	0	0	1	12	1.000	6.0	3.0	3.0	12.0	4.00
2022	27	-1.4	SEA	AL	Maj	SEA	0	0		0.00	0.00	1	0	1	0	0	0	1.0	1	0	0	0	1	0	1	0	0	0	5	2.000	9.0	0.0	9.0	9.0	1.00
2023	28	0.7	Tacoma	PCL	AAA	SEA	2	5	.286	2.29	3.11	51	3	26	0	0	15	55.0	36	19	14	2	31	1	86	5	0	3	228	1.218	5.9	0.3	5.1	14.1	2.77
2024	29	2.0	Memphis	IL	AAA	STL	1	0	1.000	1.35	2.03	14	0	1	0	0	1	13.1	8	3	2	0	5	0	9	0	0	1	52	0.975	5.4	0.0	3.4	6.1	1.80
2024	29	-0.1	STL	NL	Maj	STL	0	0		11.25	11.25	8	0	4	0	0	0	8.0	13	10	10	2	8	0	11	1	0	1	46	2.625	14.6	2.3	9.0	12.4	1.38
2025	30	2.7	Memphis	IL	AAA	STL	1	0	1.000	2.79	3.26	19	0	10	0	0	3	19.1	16	7	6	1	8	0	32	3	0	0	86	1.241	7.4	0.5	3.7	14.9	4.00
2025	30	0.9	STL	NL	Maj	STL	3	1	.750	2.06	2.44	42	0	15	0	0	6	48.0	33	13	11	2	22	2	45	7	0	3	199	1.146	6.2	0.4	4.1	8.4	2.05
2026	31	1.7	STL	NL	Maj	STL	3	3	.500	3.72	4.21	36	0	28	0	0	22	36.1	30	17	15	2	12	0	35	6	0	5	153	1.156	7.4	0.5	3.0	8.7	2.92
Year	Age	AgeDif	Tm	Lg	Lev	Aff	W	L	W-L%	ERA	RA9	G	GS	GF	CG	SHO	SV	IP	H	R	ER	HR	BB	IBB	SO	HBP	BK	WP	BF	WHIP	H9	HR9	BB9	SO9	SO/W
Majors (5 seasons)					Majors		6	5	.545	3.61	3.99	88	1	48	0	0	28	94.2	79	42	38	8	46	2	94	14	0	9	412	1.320	7.5	0.8	4.4	8.9	2.04
Minors (8 seasons)					Minors		28	25	.528	3.49	3.99	196	66	44	2	2	19	472.0	361	209	183	35	232	3	545	36	0	38	1997	1.256	6.9	0.7	4.4	10.4	2.35
College (1 season)					College		3	4	.429	2.15	3.36	20	6		0	0	4	67.0	50	25	16	0	23		81	6	0	6	281	1.090	6.7	0.0	3.1	10.9	3.52
Other (1 season)					Other		0	0		0.00	0.00	1	0	1	0	0	0	0.1	1	0	0	0	0	0	0	0	0	0	2	3.000	27.0	0.0	0.0	0.0
All Levels (10 Seasons)							37	34	.521	3.36	3.92	305	73	93	2	2	51	634.0	491	276	237	43	301	5	720	56	0	53	2692	1.249	7.0	0.6	4.3	10.2	2.39

AAA (5 seasons)					Minors		12	15	.444	4.13	4.73	140	26	41	0	0	19	240.0	198	126	110	24	129	2	295	23	0	15	1052	1.363	7.4	0.9	4.8	11.1	2.29
AA (1 season)					Minors		5	6	.455	3.93	4.33	14	11	0	1	1	0	68.2	56	33	30	4	29	0	72	6	0	8	297	1.238	7.3	0.5	3.8	9.4	2.48
A+ (2 seasons)					Minors		6	3	.667	2.68	3.16	16	14	0	1	1	0	74.0	56	26	22	3	36	1	72	1	0	7	304	1.243	6.8	0.4	4.4	8.8	2.00
A (1 season)					Minors		4	1	.800	2.05	2.61	15	5	3	0	0	0	48.1	23	14	11	3	21	0	66	2	0	5	185	0.910	4.3	0.6	3.9	12.3	3.14
Rk (1 season)					Minors		1	0	1.000	2.20	2.20	11	10	0	0	0	0	41.0	28	10	10	1	17	0	40	4	0	3	159	1.098	6.1	0.2	3.7	8.8	2.35