Since 2021, 50 pitchers are tied for the best ERA by a relief pitcher, with an ERA of 0.00. The first three are Juan Mejia, Christian Koss and Chase Lee.

	NAME	ERA	G	W	L	W%	GS	SO	CG	SHO	SV	IP	H	ER	R	HR	BB	HBP	GF	IBB	TBF	WP	K/9	BB/9	K/BB	HR/9	K%	BB%	WHIP	BABIP	RA	H/9
1	Juan Mejia J. Mejia	0.00	1	0	0		0	1	0	0	0	1.0	1	0	1	0	0	0	1	0	4	0	9.00	0.00		0.00	25.0	0.0	1.00	.333	9.00	9.00
2	Christian Koss C. Koss	0.00	1	0	0		0	0	0	0	0	1.0	1	0	0	0	0	0	1	0	4	0	0.00	0.00		0.00	0.0	0.0	1.00	.250	0.00	9.00
3	Chase Lee C. Lee	0.00	1	0	0		0	1	0	0	0	1.2	0	0	0	0	2	1	1	0	7	0	5.40	10.80	0.50	0.00	14.3	28.6	1.20	.000	0.00	0.00
4	Sauryn Lao S. Lao	0.00	1	0	0		0	3	0	0	0	1.2	3	0	1	0	0	0	1	0	8	0	16.20	0.00		0.00	37.5	0.0	1.80	.600	5.40	16.20
5	Paxton Schultz P. Schultz	0.00	1	0	0		0	8	0	0	0	4.1	2	0	0	0	0	0	0	0	16	0	16.62	0.00		0.00	50.0	0.0	0.46	.250	0.00	4.15
6	Cade Gibson C. Gibson	0.00	1	0	0		0	2	0	0	0	2.1	1	0	0	0	0	0	0	0	8	0	7.71	0.00		0.00	25.0	0.0	0.43	.167	0.00	3.86
7	Zach Agnos Z. Agnos	0.00	2	0	0		0	0	0	0	0	2.0	2	0	0	0	0	0	0	0	8	0	0.00	0.00		0.00	0.0	0.0	1.00	.250	0.00	9.00
8	Juan Morillo J. Morillo	0.00	3	0	0		0	4	0	0	0	3.0	0	0	0	0	2	0	1	0	9	0	12.00	6.00	2.00	0.00	44.4	22.2	0.67	.000	0.00	0.00
9	Matt Svanson M. Svanson	0.00	1	0	0		0	0	0	0	0	1.0	1	0	0	0	0	0	0	0	4	0	0.00	0.00		0.00	0.0	0.0	1.00	.250	0.00	9.00
10	Evan Sisk E. Sisk	0.00	2	0	0		0	5	0	0	0	2.1	2	0	0	0	2	0	1	0	11	0	19.29	7.71	2.50	0.00	45.5	18.2	1.71	.500	0.00	7.71
11	Cole Henry C. Henry	0.00	4	0	0		0	8	0	0	0	4.2	2	0	0	0	1	1	4	1	18	0	15.43	1.93	8.00	0.00	44.4	5.6	0.64	.250	0.00	3.86
12	Javier Sanoja J. Sanoja	0.00	1	0	0		0	0	0	0	0	0.2	1	0	0	0	0	0	1	0	3	0	0.00	0.00		0.00	0.0	0.0	1.50	.333	0.00	13.50
13	Ezequiel Duran E. Duran	0.00	1	0	0		0	0	0	0	0	1.0	0	0	0	0	0	0	1	0	3	0	0.00	0.00		0.00	0.0	0.0	0.00	.000	0.00	0.00
14	Trevor McDonald T. McDonald	0.00	1	0	0		0	1	0	0	0	3.0	0	0	0	0	1	0	1	0	10	0	3.00	3.00	1.00	0.00	10.0	10.0	0.33	.000	0.00	0.00
15	Tyler Heineman T. Heineman	0.00	1	0	0		0	0	0	0	0	1.0	1	0	0	0	0	0	1	0	4	0	0.00	0.00		0.00	0.0	0.0	1.00	.250	0.00	9.00
16	Spencer Arrighetti S. Arrighetti	0.00	1	0	0		0	4	0	0	0	2.1	0	0	0	0	3	1	0	0	11	0	15.43	11.57	1.33	0.00	36.4	27.3	1.29	.000	0.00	0.00
17	Jackson Jobe J. Jobe	0.00	2	0	0		0	2	0	0	0	4.0	1	0	0	0	1	0	1	0	16	0	4.50	2.25	2.00	0.00	12.5	6.3	0.50	.077	0.00	2.25
18	Michael Stefanic M. Stefanic	0.00	1	0	0		0	0	0	0	0	1.0	1	0	0	0	0	1	1	0	5	0	0.00	0.00		0.00	0.0	0.0	1.00	.250	0.00	9.00
19	Eddy Alvarez E. Alvarez	0.00	1	0	0		0	1	0	0	0	1.0	1	0	0	0	0	1	1	0	5	0	9.00	0.00		0.00	20.0	0.0	1.00	.333	0.00	9.00
20	Michael McGreevy M. McGreevy	0.00	1	1	0	1.000	0	4	0	0	0	3.0	2	0	0	0	0	0	1	0	10	0	12.00	0.00		0.00	40.0	0.0	0.67	.333	0.00	6.00
21	Andrew Walters A. Walters	0.00	8	1	0	1.000	0	6	0	0	0	7.0	1	0	1	0	5	0	3	0	27	1	7.71	6.43	1.20	0.00	22.2	18.5	0.86	.063	1.29	1.29
22	Sean Burke S. Burke	0.00	1	0	0		0	3	0	0	0	3.0	3	0	1	0	1	0	1	0	14	1	9.00	3.00	3.00	0.00	21.4	7.1	1.33	.300	3.00	9.00
23	Nick Nastrini N. Nastrini	0.00	1	0	0		0	2	0	0	0	3.1	1	0	0	0	4	0	0	0	14	0	5.40	10.80	0.50	0.00	14.3	28.6	1.50	.125	0.00	2.70
24	Luis Guerrero L. Guerrero	0.00	10	0	0		0	10	0	0	0	12.0	7	0	1	0	2	0	3	0	43	0	7.50	1.50	5.00	0.00	23.3	4.7	0.75	.226	0.75	5.25
25	Justin Wrobleski J. Wrobleski	0.00	2	0	0		0	6	0	0	1	6.0	3	0	0	0	5	1	1	0	25	0	9.00	7.50	1.20	0.00	24.0	20.0	1.33	.231	0.00	4.50