Willie Aikens has the highest career OPS in the postseason when making 40+ plate appearances, with an OPS of 1.215.

Interpreted as:

highest ops by a player in a postseason min 40 pa

	NAME	OPS	PA	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	TB	XBH	SH	SF	IBB	GIDP	AVG	OBP	SLG
1	Willie Aikens W. Aikens	1.215	49	12	40	5	15	0	1	4	10	9	0	11	0	0	29	5	0	0	0	0	.375	.490	.725
2	Lou Gehrig L. Gehrig	1.214	150	34	119	30	43	8	3	10	35	26	2	17	0	1	87	21	1		2	1	.361	.483	.731
3	Babe Ruth B. Ruth	1.214	167	41	129	37	42	5	2	15	33	33	2	30	4	3	96	22	2		2	3	.326	.470	.744
4	Bobby Brown B. Brown	1.207	46	17	41	9	18	5	3	0	9	5	0	3	0	0	29	8	0		0	0	.439	.500	.707
5	Carlos Delgado C. Delgado	1.199	43	10	37	8	13	3	0	4	11	6	0	6	0	0	28	7	0	0	0	0	.351	.442	.757
6	Troy Glaus T. Glaus	1.154	88	24	78	18	25	5	1	9	16	9	1	20	0	0	59	15	0	0	2	1	.321	.398	.756
7	Chris Young C. Young	1.138	60	15	48	10	15	3	0	5	9	11	1	19	4	2	33	8	0	0	0	0	.313	.450	.688
8	Sean Casey S. Casey	1.131	41	12	39	3	16	5	0	2	9	1	1	4	0	0	27	7	0	0	0	0	.410	.439	.692
9	Billy Hatcher B. Hatcher	1.119	61	14	52	12	21	5	1	2	6	5	1	4	3	1	34	8	3	0	1	1	.404	.466	.654
10	Hank Aaron H. Aaron	1.116	74	17	69	11	25	4	1	6	16	5	0	13	0	0	49	11	0	0	0	2	.362	.405	.710
11	Fernando Tatis Jr. F. Tatis Jr.	1.114	70	16	60	15	19	5	0	6	12	9	1	13	2	1	42	11	0	0	1	1	.317	.414	.700
12	Adolis García A. García	1.108	68	15	62	11	20	1	0	8	22	3	3	18	2	0	45	9	0	0	0	0	.323	.382	.726
13	Pepper Martin P. Martin	1.103	60	15	55	14	23	7	1	1	9	5	0	6	7	2	35	9	0		0	0	.418	.467	.636
14	Ryne Sandberg R. Sandberg	1.098	47	10	39	9	15	5	1	1	6	6	0	6	3	1	25	7	1	1	0	0	.385	.457	.641
15	Rusty Staub R. Staub	1.096	46	11	41	5	14	2	0	4	11	5	0	4	0	0	28	6	0	0	0	0	.341	.413	.683
16	Lenny Dykstra L. Dykstra	1.094	136	32	112	27	36	6	1	10	19	20	2	23	5	0	74	17	2	0	3	0	.321	.433	.661
17	Vladimir Guerrero Jr. V. Guerrero Jr.	1.091	114	24	95	19	32	6	0	8	16	16	2	12	0	0	62	14	0	1	7	2	.337	.439	.653
18	Gary Matthews G. Matthews	1.090	75	19	65	12	21	0	1	7	15	10	0	9	2	1	44	8	0	0	2	3	.323	.413	.677
19	Lou Brock L. Brock	1.079	92	21	87	16	34	7	2	4	13	5	0	10	14	2	57	13	0	0	0	0	.391	.424	.655
20	Cody Ross C. Ross	1.076	59	15	51	11	15	5	0	5	10	7	1	11	0	0	35	10	0	0	0	1	.294	.390	.686
21	Juan Gonzalez J. Gonzalez	1.075	66	15	62	11	18	4	0	8	15	4	0	15	0	0	46	12	0	0	1	2	.290	.333	.742
22	A.J. Ellis	1.065	61	17	52	7	19	5	1	2	5	7	1	9	0	0	32	8	1	0	1	0	.365	.450	.615
23	Paul Molitor P. Molitor	1.050	132	29	117	28	43	5	3	6	22	12	2	15	3	2	72	14	1	0	1	2	.368	.435	.615
24	Milton Bradley M. Bradley	1.050	47	11	42	6	13	3	0	4	8	5	0	5	2	0	28	7	0	0	0	3	.310	.383	.667
25	Carl Yastrzemski C. Yastrzemski	1.047	76	17	65	15	24	3	0	4	11	9	1	3	0	0	39	7	0	1	2	2	.369	.447	.600