The South Side Shakeup Continues With Two Weekend Trades

The White Sox rebuild marched on over the weekend, as the team signed a veteran non-roster invitee and made two trades that brought three prospects and a draft pick into the system. Most significantly, 24-year-old reliever Gregory Santos was traded to the Mariners for 23-year-old righty Prelander Berroa, 25-year-old outfielder Zach DeLoach and a “Comp B” draft pick, the 69th choice in the 2024 draft. The White Sox also traded 21-year-old righty Cristian Mena to Arizona for 26-year-old outfielder Dominic Fletcher.

Let’s begin with the Seattle deal, as it includes Santos, who is poised to have the most significant individual impact in 2024 among the players traded on Saturday. This is the third time he has been traded. Initially signed by Boston back in 2015, he was dealt to San Francisco for Eduardo Núñez in 2017, before Santos had even pitched in the United States. He spent a large portion of his time with San Francisco on the shelf, with a myriad of shoulder issues and a PED suspension. During his time in the Red Sox and Giants organizations, Santos never pitched more than 50 innings in a single season, even when he was being developed as a starter. His stuff was still nasty enough that at one point he was a Top 100 prospect here at the site. The gargantuan youngster was sitting 97-100 (without effective movement) and bending in a plus-plus slider, essentially a hype-less Kumar Rocker.

After two seasons on San Francisco’s 40-man roster, the second one again interrupted by injury, the Giants designated him for assignment while he was pitching (poorly) for Estrellas Orientales in the Dominican Winter League last offseason. The White Sox traded 28-year-old depth starter Kade McClure for him, and he became one of the few positives for them last year. Across 66 innings of work, mostly in a late-inning capacity, Santos struck out a batter per inning, got ground balls at an excellent 52% clip, and posted a 3.39 ERA. (His fielding independent stats were better than that.) The White Sox successfully added sink to Santos’ fastball, which sat roughly 99 mph all season. He paired that sinker nicely with his dastardly low-90s slider, his most frequent offering, which he has a better feel for locating. His season ended in mid-September, when he was shut down with elbow inflammation.

The Mariners have a penchant for slider-first relievers who throw really hard, and pitchers whose fastballs play down despite premium velocity. Over the last few years, they’ve traded for Andrés Muñoz, Matt Brash, Carlos Vargas, and now Santos (among others), and have had success with them. Santos joins Muñoz, Brash, and lefty Gabe Speier in the contender-quality collection of relievers at the back end of the Seattle bullpen. Santos was a rookie in 2023 and is under team control for another five years.

There is some risk involved in this trade for the Mariners. Santos has an extensive injury history, and Berroa, one of the players Seattle gave up, could quickly become about as good as Santos. That said, this is still a smart move for the Mariners. The 2024 draft class is not especially strong, so they won’t exactly miss the pick they gave to the White Sox, no matter how nice it is. Additionally, Seattle has a surplus of lefty-hitting outfielders — among them Cade Marlowe, Taylor Trammell, Dominic Canzone, and the newly acquired Luke Raley — that made DeLoach expendable. Santos has a better major league track record than Berroa, and Santos is definitely more of a prototypical big leaguer in terms of size and build. What the Mariners end up doing with their recently vacated 40-man spot is going to be a key component to evaluating this trade, but it certainly would make sense for them to add to the second rung of their bullpen.

Just as it makes sense for the Mariners to acquire Santos, so too does it for the White Sox to let him go, even though he has five years of control remaining. Setup men are much less valuable for rebuilding teams than for contenders, and the South Siders won’t be in contention for at least the next few seasons. The White Sox also were smart to recognize that Santos’ injury history is such his trade value might not get any higher than it is now.

I am not a DeLoach fan, per se. He’s a below-average corner defender with above-average power and a below-average hit tool. It’s plausible, like Jake Fraley before him, that with extended big league playing time DeLoach can improve his hit tool enough to be a corner platoon piece, and the White Sox are one of the few teams who might have a two- or three-year window to find out. However, it’s more likely to me that he’s a Quad-A hitter.

Berroa and the draft pick, which will add just over $1 million to Chicago’s draft bonus pool this year, are both good pieces to acquire. Like Santos, Berroa has also been traded multiple times. He originally signed with the Twins, who sent him to the Giants as part of a pretty big trade package for Sam Dyson (whoops) in 2019. San Francisco then traded him to Seattle early in 2022 for upper-level depth infielder Donovan Walton. He is a favorite of pitch data nerds because his 96-99 mph fastball has plus-plus quantifiable movement and his upper-80s slider generated an incredible 55% miss rate in 2023, per Synergy Sports. He struck out 37% of opposing hitters at Double-A Arkansas and has the raw stuff to pitch in the back of a bullpen if he can dial in his 30-grade control.

Berroa is built like Jason Motte and has a similarly violent and inconsistent delivery. Like a lot of pitchers who have passed through the Mariners and Giants systems in recent years, he throws his slider more often than his fastball and has a better feel for landing it in the zone. Even so, poor command is a major issue for Berroa, whose best walk rate over the last three seasons was his 12.6% mark in 2021, and he was arguably too wild for a contending team like Seattle to count on this year. The White Sox, though, can afford to be patient with him as he develops, and because Berroa is entering his second option year, they have the flexibility to move him between the majors and minors.

What motivated Chicago’s trade with Arizona, in which they moved Mena for Fletcher, is a little less obvious. There’s some roster pressure put on Mena because he probably has to add fastball velocity in order to be a good big league starter and, now that he is on the 40-man, he only has his option years to do it. It’s more common for a contending team to trade away someone like Mena, because contenders typically don’t want a developmental player occupying a 40-man spot. That said, the Diamondbacks’ situation is different from other contenders: Because they have enough pitchers who are big league ready, they can carry Mena on the 40-man and let him develop in the minors. This transaction is a bit puzzling for the White Sox because they seemingly had time to see if Mena’s velo would pop.

Mena is a smart pickup for the Diamondbacks considering how duplicative Fletcher was on their roster. For the last couple of seasons, they have had a host of small-framed, lefty-hitting outfielders on their 40-man roster, and the addition of Joc Pederson added to the logjam. A full Mena scouting report can be found on The Board.

Fletcher debuted in late April and hit an impressive .301/.350/.441 in a 28-game big league stint, but his .263 xwOBA was considerably lower than his actual .340 mark. He is a bit chase-prone, especially against high fastballs. He has become surprisingly buff for a 5-foot-9 hitter, but as he has bulked up, he has retained fluidity in his hips and shoulders, both of which are evident as he finishes his swing. The sweeping nature of his bat path means Fletcher does most of his extra-base damage against slow stuff that he can scoop at the bottom of the zone. He inside-outs a lot of fastballs the other way, and pitchers can limit his damage by approaching him with heat. Contrary to the way he was projected in high school, he now has a power-over-hit profile.

Fletcher is an average runner from home to first and doesn’t have the pure speed to play center field regularly, but his reads and routes out there are good enough for him to moonlight there in an emergency. He projects as a part time corner outfielder who teams can win with, but they probably won’t win because of him. He’ll compete with DeLoach, Andrew Benintendi, Oscar Colás, and perhaps Gavin Sheets for playing time in the corner outfield alongside franchise pillar, center fielder Luis Robert Jr. Speaking of pillars, veteran outfielder Kevin Pillar was signed to a minor league deal with an invite to Spring Training over the weekend, and figures to be in the mix for at-bats against lefties if he can make the team. Pillar is more accomplished than we should expect any of the players involved in these trades to become. He has somehow not won a Gold Glove during his 11-season big league career. At 35, he’s still capable of slugging left-handed pitching, and he joins catcher Martín Maldonado as a newly acquired vibe-cultivating veteran on a team with a clubhouse in transition.

Berroa and Fletcher have been moved over to the White Sox prospect list on The Board, which you can find here.