Tactical moves that undermine player confidence: how much should a manager consider it?

Ironically Yankee manager Joe Girardi shows confidence in many ways, including keeping a player in the lineup when many question that.  Consider Stephen Drew, playing despite a very low batting average.

However, Girardi can generally be a "Nervous Nellie" type of manager, running to his most trusted relief pitchers in situations when they could/should be rested.  In each of the last two games Girardi made tactical moves that would obviously weaken a player's self esteem and confidence.  Girardi knew that but made the moves anyway.  He must have been conflicted but went "Nervous Nellie" approach both times.

Tuesday, August 4, 2015, 7:05 pm, Yankee Stadium III
Attendance: 48,522, Time of Game: 3:26
Yankees 13, Red Sox 3

Leading 4-3 the Yankees broke open the close game with nine runs in the bottom of the 7th but by then Girardi had already made his move.

Pitching	IP	H	R	ER	BB	SO	HR	ERA	BF	Pit	Str	Ctct	StS	StL	GB	FB	LD	Unk	GSc	IR	IS	WPA	aLI	RE24
Masahiro Tanaka, W (8-4)	6	5	3	3	1	3	1	3.84	23	88	56	35	7	14	6	13	5	0	52			-0.100	1.05	-0.2
Justin Wilson, H (19)	0.2	1	0	0	0	1	0	2.61	3	15	11	5	3	3	0	2	1	0		0	0	0.029	1.73	0.2
Dellin Betances, H (16)	0.1	0	0	0	1	1	0	1.31	2	11	5	1	1	3	0	0	0	0		1	0	0.064	3.15	0.3
Branden Pinder	1	0	0	0	0	0	0	2.45	3	9	7	4	1	2	3	0	0	0		0	0	0.000	0.00	0.5
Nick Rumbelow	1	1	0	0	0	0	0	1.69	4	20	13	6	1	6	2	2	0	0		0	0	0.000	0.00	0.5
Team Totals	9	7	3	3	2	5	1	3.00	35	143	92	51	13	28	11	17	6	0	52	1	0	-0.007	1.15	1.2

It looks conventional enough.  Lefty relief pitcher Wilson is shown with three batters faced and two thirds of an inning pitched.  Set up man Betances, who usually pitches the 8th inning, got the last out in the 7th and then after the Yankees 9 run outburst Girardi was calm enough to use two unknown pitchers to hold the ten run lead in the 8th and 9th.

Here's what happened in that 7th inning.  Pablo Sandoval, batting lefty exclusively now, led off with a home run off starting pitcher Masahiro Tanaka cutting the Yankee lead to 4-3.  Girardi replaced righty Tanaka with lefty Wilson:
- righty Mike Napoli struck out
- righty Rusney Castillo pinch hit for lefty Alejandro De Aza and singled
- switch hitter Blake Swihart fouled out to first
- lefty Jackie Bradley batted; Castillo stole second; Girardi went to the mound during the Bradley plate appearance and replaced Wilson with righty Betances; Betances threw a wild pitch and Castillo advanced to third; Betances walked Bradley
- righty Brock Holt batted.  Bradley stole second.  Betances struck out Holt leaving runners on second and third.

Jackie Bradley: BA .109, OBP .232, SLG .174, OPS .406; one home run in 49 at bats this season.  Jackie Bradley is a lefty batter who cannot hit.  Lefty pitcher Justin Wilson was removed during the Bradley plate appearance.  Wilson must have been humiliated.  I wouldn't have blamed him if he had confronted Girardi on the mound and refused to give him the ball.  It was not even a big risk to let Wilson continue to pitch to Bradley.  Since it was lefty on lefty, it made sense.  Wilson said all the right things after the game, which is to say he did not tell how he really felt.  I cannot imagine how things could be right between Girardi and Wilson no matter what either said.
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Wednesday, August 5, 2015, 7:05pm, Yankee Stadium III
Attendance: 47,489, Time of Game: 2:51
Red Sox 2, Yankees 1

This was the major league debut of Yankee right handed starting pitcher Luis Severino.  In the bottom of the 9th the Yanks trailed 2-1.  Red Sox pitcher Koji Uehara entered to save the game.  With two out and a runner on second base who could tie the game Uehara walked switch hitter Chase Headley, whose error had let the first run (unearned) to score. The Red Sox preferred to put the winning run on base and pitch to lefty Didi Gregorius. Gregorius has been on an unprecedented hot streak. His OPS in this his first Yankee season replacing Derek Jeter at shortstop is only .657. That may not seem like much but here are his OPS through the end of these months in 2015:
April .499
May .580
June .610
July .655
Obviously, Gregorius has been making steady progress and now he had an opportunity to tie or even win the game for the Yankees. The kind of thing that Jeter might do. It could build confidence. But Gregorius never got the chance. Girardi removed Gregorius for pinch hitter Brian McCann who flied to center ending the game.

Joe Girardi was a catcher for 15 years; he played in 1,277 games with 4,535 PA.  Girardi was the starting catcher on the 1996 Yankee championship team, their first since 1978.  But Girardi played at least 100 games only five times.  Girardi knows about struggling to make good.  Girardi also knows about a light hitter getting a big hit in a big moment: Girardi tripled off Hall of Fame pitcher Greg Maddux in the sixth and final game of the 1996 World Series.

Girardi has managed nine years, eight for the Yankees: 786-616.  If Girardi doesn't have more sense by now than those two examples in his most recent games show, then he never will.