Aaron Boone's Wandy Peralta usage Sunday was a low-urgency disaster for Yankees

Typically, Aaron Boone is a caretaker for the Yankees more than an actively detrimental force. On Sunday afternoon, he was judge, jury and executioner.

Stuck in between buying and selling at the trade deadline, Brian Cashman sadly decided to do nothing (except add Keynan Middleton to the middle of the bullpen). No matter how you felt about this Yankees roster, that was the wrong course of action.

When selling was still in play, there was a clear reason why left-hander Wandy Peralta was in the league's crosshairs. Peralta has been a steady (occasionally exceptional) performer for this team in recent years, and helped guide the Yankees bullpen through last season's ALDS against Cleveland. He also enters free agency this offseason harboring a walk-filled set of advanced metrics that would seem to indicate regression is en route.

The Yankees, unlikely to re-sign Peralta, could've sold high. Once they opted into keeping him, though, the least they could've done was maximize his usefulness. Peralta crushes left-handers and is more susceptible to righties. After he worked out of a jam Sunday against Houston by retiring the fearsome Yordan Álvarez and Kyle Tucker, Peralta lowered his BA against lefties to .119 with a .169 SLG, per James Smyth, good for fifth and seventh in MLB with a minimum of 50 batters faced.

Very good! With Gerrit Cole on the mound on Monday against the scuffling White Sox and a number of other righties in the bullpen (including the aforementioned Middleton), the sixth inning should've belonged to someone else. Instead, because Boone and the Yankees have a set-in-stone strategy for bullpen rest that apparently cannot be changed, Peralta started the sixth against a mess of righties. He walked Chas McCormick. He allowed a single to Jeremy Peña. Then, Jake Meyers, a light-hitting outfielder, drilled his second home run of the day. Martin Maldonado followed with another dinger. None of this should've been allowed to happen.

Why did Aaron Boone hang Yankees left-hander Wandy Peralta out to dry vs Astros?

Middleton entered in the seventh, for the textbook definition of a "too little, too late" effort. To add insult to injury, he started his outing by facing (and retiring) Álvarez and Tucker.

"Too little, too late" feels familiar, considering it's how Middleton arrived in the first place, and the reason Peralta is still here.

We know what Boone was thinking. His other top relievers worked together to secure a life-affirming win on Saturday, tossing five one-hit innings. Clay Holmes pitched Thursday and Saturday; he'd be out, context be damned. Michael King pitched Thursday and Saturday; not a chance he'd be used. Even in the thick of the Wild Card race, Boone cannot be disrupted. He will do what he intended to do, regardless of the shifting circumstances and which starter is pitching the next day.

Middleton breezed through the heart of the order in the seventh, indicating he could've probably done so in the sixth as well. We'll never know. Instead, Peralta was allowed to regress in one fell swoop and allow two (predictable) home runs in an outing for the first time in his Yankees career.

We should've left Sunday's game lauding Peralta's effort. Instead, we're left lamenting him. That one's on Boone and his inflexibility.