Riley O'Brien #55

P
B/T: R/R
6' 4"/180
Age: 30

2025 Regular Season

G	W-L	ERA	IP	SO	WHIP
23	1-0	1.93	28.0	29	1.21

G	W-L	ERA	IP	SO	WHIP
23	1-0	1.93	28.0	29	1.21

Career Regular Season

G	W-L	ERA	IP	SO	WHIP
33	1-1	4.23	38.1	43	1.62

G	W-L	ERA	IP	SO	WHIP
33	1-1	4.23	38.1	43	1.62

Riley O'Brien Bio

Fullname: Riley Chun-Young O'Brien
Born: 2/06/1995 in Seattle, WA
Draft: 2017, Tampa Bay Rays, Round: 8, Overall Pick: 229
College: College of Idaho
Debut: 9/28/2021

Year	W	L	ERA	G	GS	SV	IP	SO	WHIP
2025 Regular Season	1	0	1.93	23	0	0	28.0	29	1.21
Career Regular Season	1	1	4.23	33	1	0	38.1	43	1.62

Year	W	L	ERA	G	GS	SV	IP	SO	WHIP
2025 Regular Season	1	0	1.93	23	0	0	28.0	29	1.21
Career Regular Season	1	1	4.23	33	1	0	38.1	43	1.62

Status: Active
Next STL Game: 08-06 @ LAD

Splits

Duration	W	ERA	G	IP	H	ER	BB	SO	WHIP
Last 7 Games	1	1.23	7	7.1	4	1	4	8	1.09
Last 15 Games	1	1.08	15	16.2	11	2	10	23	1.26
Last 30 Games	1	1.93	23	28.0	21	6	13	29	1.21

Duration	W	ERA	G	IP	H	ER	BB	SO	WHIP
Last 7 Games	1	1.23	7	7.1	4	1	4	8	1.09
Last 15 Games	1	1.08	15	16.2	11	2	10	23	1.26
Last 30 Games	1	1.93	23	28.0	21	6	13	29	1.21

Last 3 Games	W	IP	H	ER	SO
8/4 @ LAD	1	1.0	1	1	0
7/30 vs MIA	0	1.1	0	0	1
7/26 vs SD	0	1.0	0	0	1

Last 3 Games	W	IP	H	ER	SO
8/4 @ LAD	1	1.0	1	1	0
7/30 vs MIA	0	1.1	0	0	1
7/26 vs SD	0	1.0	0	0	1

Games by Position: RP (23)

Awards

APP Pitcher of the Week

Week	Team	League
07/02/2017	Princeton Rays	APP
08/06/2017	Princeton Rays	APP

MID Mid-Season All-Star

Year	Team	League
2018	Bowling Green Hot Rods	MID

PCL Post-Season All-Star

Year	Team	League
2023	Tacoma Rainiers	PCL

Latest Transactions

Team	Date	Transaction
	June 9, 2025	St. Louis Cardinals recalled RHP Riley O'Brien from Memphis Redbirds.
	June 6, 2025	St. Louis Cardinals optioned RHP Riley O'Brien to Memphis Redbirds.
	June 5, 2025	St. Louis Cardinals recalled RHP Riley O'Brien from Memphis Redbirds.
	May 2, 2025	St. Louis Cardinals optioned RHP Riley O'Brien to Memphis Redbirds.
	April 25, 2025	St. Louis Cardinals recalled RHP Riley O'Brien from Memphis Redbirds.
	March 15, 2025	St. Louis Cardinals optioned RHP Riley O'Brien to Memphis Redbirds.
	March 15, 2025	Memphis Redbirds activated RHP Riley O'Brien.
	August 27, 2024	St. Louis Cardinals recalled RHP Riley O'Brien from Memphis Redbirds.
	August 11, 2024	St. Louis Cardinals optioned RHP Riley O'Brien to Memphis Redbirds.
	August 11, 2024	St. Louis Cardinals activated RHP Riley O'Brien from the 60-day injured list.
	July 19, 2024	St. Louis Cardinals sent RHP Riley O'Brien on a rehab assignment to Memphis Redbirds.
	July 19, 2024	St. Louis Cardinals sent RHP Riley O'Brien on a rehab assignment to Memphis Redbirds.
	May 10, 2024	St. Louis Cardinals transferred RHP Riley O'Brien from the 15-day injured list to the 60-day injured list. Right forearm flexor strain.
	March 31, 2024	St. Louis Cardinals placed RHP Riley O'Brien on the 15-day injured list retroactive to March 29, 2024. Right forearm flexor strain.
	November 5, 2023	Seattle Mariners traded RHP Riley O'Brien to St. Louis Cardinals for cash.
	January 31, 2023	Seattle Mariners invited non-roster RHP Riley O'Brien to spring training.
	January 31, 2023	RHP Riley O'Brien roster status changed by Seattle Mariners.
	July 26, 2022	Tacoma Rainiers activated RHP Riley O'Brien.
	July 26, 2022	Tacoma Rainiers activated RHP Riley O'Brien.
	June 30, 2022	Tacoma Rainiers transferred RHP Riley O'Brien to the Development List.
	June 2, 2022	Seattle Mariners sent RHP Riley O'Brien outright to Tacoma Rainiers.
	May 27, 2022	Seattle Mariners designated RHP Riley O'Brien for assignment.
	May 8, 2022	Seattle Mariners optioned RHP Riley O'Brien to Tacoma Rainiers.
	May 5, 2022	Seattle Mariners recalled RHP Riley O'Brien from Tacoma Rainiers.
	April 17, 2022	Seattle Mariners optioned RHP Riley O'Brien to Tacoma Rainiers.
	April 17, 2022	RHP Riley O'Brien assigned to Louisville Bats.
	April 13, 2022	Cincinnati Reds designated RHP Riley O'Brien for assignment.
	March 27, 2022	Cincinnati Reds optioned RHP Riley O'Brien to Louisville Bats.
	March 27, 2022	Louisville Bats activated RHP Riley O'Brien.
	October 5, 2021	Cincinnati Reds recalled RHP Riley O'Brien from Louisville Bats.
	September 30, 2021	Cincinnati Reds optioned RHP Riley O'Brien to Louisville Bats.
	September 28, 2021	Cincinnati Reds recalled RHP Riley O'Brien from Louisville Bats.
	May 4, 2021	RHP Riley O'Brien assigned to Louisville Bats from Reds Alternate Training Site.
	March 29, 2021	P Riley O'Brien assigned to Reds Alternate Training Site from Louisville Bats.
	March 12, 2021	Cincinnati Reds optioned P Riley O'Brien to Louisville Bats.
	February 3, 2021	Riley O'Brien changed number to 84.
	November 20, 2020	Cincinnati Reds selected the contract of RHP Riley O'Brien from Chattanooga Lookouts.
	October 2, 2020	RHP Riley O'Brien assigned to Chattanooga Lookouts from Reds Alternate Training Site.
	August 28, 2020	RHP Riley O'Brien assigned to Reds Alternate Training Site.
	August 28, 2020	Tampa Bay Rays traded Riley O'Brien to Cincinnati Reds for LHP Cody Reed.
	September 9, 2019	Montgomery Biscuits activated RHP Riley O'Brien from the 7-day injured list.
	July 26, 2019	Montgomery Biscuits placed RHP Riley O'Brien on the 7-day injured list.
	May 7, 2019	RHP Riley O'Brien assigned to Montgomery Biscuits from Charlotte Stone Crabs.
	April 1, 2019	RHP Riley O'Brien assigned to Charlotte Stone Crabs from Montgomery Biscuits.
	February 23, 2019	RHP Riley O'Brien assigned to Tampa Bay Rays.
	September 11, 2018	RHP Riley O'Brien assigned to Montgomery Biscuits from Durham Bulls.
	September 5, 2018	RHP Riley O'Brien assigned to Durham Bulls from Charlotte Stone Crabs.
	August 26, 2018	Charlotte Stone Crabs activated RHP Riley O'Brien from the 7-day disabled list.
	August 10, 2018	Charlotte Stone Crabs placed RHP Riley O'Brien on the 7-day disabled list retroactive to August 9, 2018.
	June 23, 2018	RHP Riley O'Brien assigned to Charlotte Stone Crabs from Bowling Green Hot Rods.
	June 18, 2018	RHP Riley O'Brien assigned to MID East Division All-Stars.
	April 2, 2018	RHP Riley O'Brien assigned to Bowling Green Hot Rods from Princeton Rays.
	June 21, 2017	RHP Riley O'Brien assigned to Princeton Rays.
	June 20, 2017	Tampa Bay Rays signed RHP Riley O'Brien.

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