Wandy Peralta to NL West (Dodgers, Diamondbacks)
The sooner the Yankees get Peralta out the door, the better, according to the advanced metrics. He's a pure rental; the lefty reliever's contract is up at the end of the season. He's been a left-handed workhorse and a breath of fresh air for the Yanks for the better part of two seasons. Still ... the underlying numbers don't lie.
Peralta's walk rate has been rough this season (5th percentile), leaving his FIP in a disastrous zone (4.77, despite a sterling 2.48 ERA). His expected ERA and batting average against are in the 20th and 25th percentile, respectively. A desperate team looking for bullpen help and a wealth of experience might be happy to surrender a mid-tier prospect and hope those things don't correct themselves in the second half. Considering Peralta's rental status and the Yankees' recent free fall, they should feel very little compunction to keep him (and, again, they've been ruthless lately and probably won't).
The Dodgers will be looking for any number of bullpen upgrades, but perhaps won't be as willing to analytically roll the dice as a desperate team like the Diamondbacks, fighting off a midseason slide and looking to reestablish themselves as contenders (Wild Card or NL West variety). Remember, every MLB team has access to these same regression metrics. We're not special because we scrolled Savant. It just comes down to a gamble. Are you buying Peralta, the postseason weapon from 2022 and solid fireman for the past two seasons? Or are you selling his first half?