I couldn't find anything for this season, but Patrick Baldwin Jr. had the highest plus/minus in losses in 2024-25, at +37.

Interpreted as:

biggest +/- in losses by a player this season

	NAME	+/-	L	SEASON	TM	GP	MPG	PPG	RPG	APG	SPG	BPG	FGM	FGA	FG%	3PM	3PA	3P%	FTM	FTA	FT%	TS%	OREB	DREB	TPG	MIN	PTS	REB	AST	STL	BLK	TOV	PF
1	Patrick Baldwin Jr. P. Baldwin Jr.	+37	21	2024-25	WAS	21	4.6	2.1	1.0	0.1	0.1	0.1	0.8	1.5	51.6	0.5	1.0	52.4	0.1	0.2	50.0	68.7	0.2	0.8	0.2	98	45	22	2	3	2	5	5
2	Jordan McLaughlin J. McLaughlin	+33	29	2024-25	TOT	29	6.6	2.2	0.7	1.1	0.3	0.0	0.7	1.4	48.8	0.4	0.9	44.4	0.4	0.6	81.3	67.7	0.2	0.5	0.3	192	65	19	33	8	1	10	9
3	MarJon Beauchamp M. Beauchamp	+33	16	2024-25	TOT	16	6.1	3.1	1.6	0.5	0.2	0.0	1.1	2.5	42.5	0.4	0.9	42.9	0.6	0.9	71.4	54.2	0.6	1.1	0.6	97	50	26	8	3	0	9	10
4	Doug McDermott D. McDermott	+33	21	2024-25	SAC	21	9.7	4.2	0.6	0.1	0.0	0.0	1.5	3.1	47.7	1.2	2.7	44.6	0.0	0.1	50.0	66.8	0.1	0.5	0.1	204	88	12	3	1	1	2	20
5	Harrison Ingram H. Ingram	+30	5	2024-25	SAS	5	7.0	0.8	1.8	0.6	0.6	0.0	0.4	0.8	50.0	0.0	0.2	0.0	0.0	0.0		50.0	0.4	1.4	0.2	35	4	9	3	3	0	1	2
6	David Duke Jr. D. Duke Jr.	+28	6	2024-25	SAS	6	5.6	2.7	0.8	0.7	0.2	0.0	1.0	2.3	42.9	0.5	1.0	50.0	0.2	0.3	50.0	53.8	0.2	0.7	0.3	34	16	5	4	1	0	2	1
7	Tyler Smith T. Smith	+25	11	2024-25	MIL	11	5.2	2.6	1.1	0.3	0.2	0.2	1.0	2.5	40.7	0.5	1.4	33.3	0.2	0.4	50.0	50.4	0.2	0.9	0.5	58	29	12	3	2	2	5	5
8	Jared Rhoden J. Rhoden	+23	6	2024-25	TOT	6	10.0	5.2	2.0	0.8	0.3	0.2	1.8	3.8	47.8	0.2	1.3	12.5	1.3	1.5	88.9	57.5	1.0	1.0	0.7	60	31	12	5	2	1	4	4
9	Jevon Carter J. Carter	+23	23	2024-25	CHI	23	10.4	5.0	1.1	1.5	0.6	0.0	1.8	4.7	38.9	1.2	3.3	36.8	0.1	0.2	50.0	51.9	0.1	1.0	0.3	239	114	26	35	13	1	8	13
10	Jazian Gortman J. Gortman	+20	8	2024-25	DAL	8	4.2	1.6	0.4	0.6	0.1	0.0	0.6	1.8	35.7	0.1	0.6	20.0	0.3	0.5	50.0	41.2	0.0	0.4	0.6	33	13	3	5	1	0	5	5
11	Neemias Queta N. Queta	+19	16	2024-25	BOS	16	13.2	4.1	4.0	0.8	0.3	0.8	1.6	2.5	62.5	0.0	0.0		0.9	1.3	75.0	66.6	1.6	2.4	0.6	211	65	64	13	4	12	10	21
12	Damion Lee D. Lee	+18	19	2024-25	PHX	19	5.4	3.9	0.7	0.3	0.3	0.0	1.2	3.3	37.1	0.4	1.6	26.7	1.1	1.1	95.2	51.9	0.1	0.6	0.4	103	74	13	6	5	0	7	4
13	Luka Garza L. Garza	+18	11	2024-25	MIN	11	7.4	3.7	1.5	0.5	0.4	0.1	1.2	2.9	40.6	0.3	1.3	21.4	1.1	1.7	63.2	50.8	0.8	0.7	0.2	81	41	17	6	4	1	2	14
14	Josh Minott J. Minott	+18	14	2024-25	MIN	14	5.6	3.3	0.9	0.5	0.4	0.3	1.3	2.2	58.1	0.3	0.9	33.3	0.4	0.4	100.0	68.4	0.4	0.4	0.2	79	46	12	7	5	4	3	14
15	Jackson Rowe J. Rowe	+16	2	2024-25	GSW	2	14.6	3.0	3.0	1.0	1.0	0.0	1.0	4.0	25.0	1.0	3.5	28.6	0.0	1.0	0.0	33.8	0.0	3.0	0.0	29	6	6	2	2	0	0	4
16	Elijah Harkless E. Harkless	+16	9	2024-25	UTA	9	13.3	3.2	2.0	0.8	1.0	0.1	1.1	3.3	33.3	0.7	2.3	28.6	0.3	0.4	75.0	45.7	0.9	1.1	0.2	119	29	18	7	9	1	2	13
17	Dillon Jones D. Jones	+15	9	2024-25	OKC	9	9.7	2.7	2.8	1.3	0.0	0.1	1.0	1.8	56.3	0.4	1.1	40.0	0.2	0.4	50.0	67.6	1.3	1.4	0.4	88	24	25	12	0	1	4	6
18	Phillip Wheeler P. Wheeler	+13	5	2024-25	PHI	5	8.9	1.6	1.6	0.4	0.2	0.4	0.6	4.2	14.3	0.0	2.0	0.0	0.4	0.4	100.0	18.3	0.4	1.2	0.2	44	8	8	2	1	2	1	1
19	Trentyn Flowers T. Flowers	+13	2	2024-25	LAC	2	7.9	4.5	2.0	0.0	0.0	0.0	2.0	4.5	44.4	0.0	1.0	0.0	0.5	0.5	100.0	47.7	0.5	1.5	0.5	16	9	4	0	0	0	1	3
20	Chris Duarte C. Duarte	+13	13	2024-25	CHI	13	4.6	2.8	1.1	0.5	0.0	0.0	0.9	1.7	54.5	0.5	0.9	50.0	0.5	0.6	75.0	70.5	0.2	0.8	0.0	60	36	14	7	0	0	0	4
21	Drew Peterson D. Peterson	+12	8	2024-25	BOS	8	8.0	2.8	1.3	0.4	0.3	0.0	0.9	2.0	43.8	0.8	1.8	42.9	0.3	0.3	100.0	65.2	0.3	1.0	0.4	64	22	10	3	2	0	3	7
22	Daeqwon Plowden D. Plowden	+11	3	2024-25	ATL	3	4.5	1.7	1.0	0.0	0.0	0.0	0.3	1.0	33.3	0.3	1.0	33.3	0.7	0.7	100.0	64.4	0.0	1.0	0.0	14	5	3	0	0	0	0	2
23	Branden Carlson B. Carlson	+11	3	2024-25	OKC	3	4.3	3.0	1.0	0.3	0.0	0.3	1.0	1.3	75.0	1.0	1.3	75.0	0.0	0.0		112.5	0.0	1.0	0.7	13	9	3	1	0	1	2	3
24	Cam Christie C. Christie	+11	3	2024-25	LAC	3	8.3	1.7	1.7	0.3	0.7	0.0	0.7	2.7	25.0	0.3	1.7	20.0	0.0	0.0		31.3	0.3	1.3	0.7	25	5	5	1	2	0	2	1
25	Mac McClung M. McClung	+11	1	2024-25	ORL	1	4.9	0.0	1.0	2.0	0.0	0.0	0.0	0.0		0.0	0.0		0.0	0.0			0.0	1.0	0.0	5	0	1	2	0	0	0	0