I couldn't find anything for this season, but Duke Ellis had the highest batting average after the All-Star Game in 2024, with an average of 1.000 in his rookie season.

Interpreted as:

highest average by a player since all star break this season

	NAME	AVG	SEASON	TM	G	AB	R	H	2B	3B	HR	RBI	BB	HBP	SO	SB	CS	PA	TB	XBH	SH	SF	IBB	GIDP	OBP	SLG	OPS
1	Duke Ellis D. Ellis	1.000	2024	NYY	3	1	0	1	0	0	0	0	0	0	0	1	0	1	1	0	0	0	0	0	1.000	1.000	2.000
2	Stone Garrett S. Garrett	.600	2024	WSH	2	5	2	3	1	0	1	3	1	0	0	0	0	6	7	2	0	0	0	0	.667	1.400	2.067
3	Darren Baker D. Baker	.500	2024	WSH	9	14	1	7	2	0	0	0	0	0	3	0	0	14	9	2	0	0	0	0	.500	.643	1.143
4	Jakson Reetz J. Reetz	.500	2024	SFG	1	2	0	1	1	0	0	0	1	0	1	0	0	3	2	1	0	0	0	0	.667	1.000	1.667
5	Diego Castillo D. Castillo	.500	2024	MIN	3	4	2	2	1	0	0	2	1	0	1	0	0	5	3	1	0	0	0	0	.600	.750	1.350
6	Austin Shenton A. Shenton	.400	2024	TBR	2	5	0	2	1	0	0	0	1	0	1	0	0	6	3	1	0	0	0	1	.500	.600	1.100
7	Luis Urías L. Urías	.400	2024	SEA	7	15	3	6	3	0	1	4	2	1	3	0	0	18	12	4	0	0	0	0	.500	.800	1.300
8	Vladimir Guerrero Jr. V. Guerrero Jr.	.376	2024	TOR	63	242	50	91	23	1	16	46	31	3	28	0	2	278	164	40	0	2	11	7	.450	.678	1.127
9	Blake Dunn B. Dunn	.375	2024	CIN	7	8	4	3	0	0	1	1	1	0	4	2	0	9	6	1	0	0	0	0	.444	.750	1.194
10	Bo Bichette B. Bichette	.375	2024	TOR	2	8	0	3	0	0	0	1	0	0	1	0	0	8	3	0	0	0	0	0	.375	.375	.750
11	Iván Herrera I. Herrera	.368	2024	STL	18	57	13	21	6	0	2	8	10	0	12	1	0	67	33	8	0	0	0	1	.463	.579	1.042
12	Kyle Tucker K. Tucker	.365	2024	HOU	18	63	14	23	2	0	4	9	10	1	13	1	0	75	37	6	0	1	2	0	.453	.587	1.041
13	Alex Call A. Call	.349	2024	WSH	23	83	9	29	8	0	3	13	9	0	14	4	1	92	46	11	0	0	0	2	.413	.554	.967
14	Jonatan Clase J. Clase	.348	2024	TOT	9	23	3	8	1	0	1	2	2	2	4	0	1	27	12	2	0	0	0	0	.444	.522	.966
15	Aaron Judge A. Judge	.347	2024	NYY	62	216	49	75	12	0	24	59	61	3	65	5	0	280	159	36	0	0	14	8	.496	.736	1.233
16	Bobby Witt Jr. B. Witt Jr.	.345	2024	KCR	64	249	50	86	20	2	16	46	29	4	35	9	3	284	158	38	0	2	5	2	.419	.635	1.054
17	Dustin Harris D. Harris	.333	2024	TEX	2	6	1	2	1	0	1	3	1	0	2	0	0	7	6	2	0	0	0	0	.429	1.000	1.429
18	Vaughn Grissom V. Grissom	.333	2024	BOS	8	24	4	8	2	0	0	3	2	0	5	2	0	27	10	2	0	1	0	1	.370	.417	.787
19	César Salazar C. Salazar	.333	2024	HOU	3	3	0	1	0	0	0	0	0	0	2	0	0	3	1	0	0	0	0	0	.333	.333	.667
20	Drew Millas D. Millas	.333	2024	WSH	9	27	5	9	0	0	0	0	3	0	8	2	0	30	9	0	0	0	0	0	.400	.333	.733
21	Hunter Feduccia H. Feduccia	.333	2024	LAD	5	12	2	4	0	0	0	1	2	0	2	0	0	14	4	0	0	0	0	1	.429	.333	.762
22	Forrest Wall F. Wall	.333	2024	MIA	3	3	1	1	0	0	0	0	0	0	2	1	0	3	1	0	0	0	0	0	.333	.333	.667
23	Andrew Knizner A. Knizner	.333	2024	TEX	3	9	0	3	0	0	0	2	0	0	2	0	0	9	3	0	0	0	0	0	.333	.333	.667
24	Zack Short Z. Short	.333	2024	ATL	4	3	1	1	1	0	0	0	1	0	2	0	0	5	2	1	1	0	0	0	.500	.667	1.167
25	Jack Suwinski J. Suwinski	.333	2024	PIT	5	12	0	4	1	0	0	0	1	0	4	3	0	13	5	1	0	0	0	0	.385	.417	.801