The White Sox’ Improbable Breakout

To call Peters an out-of-the-blue breakout would be a disservice to other out-of-the-blue breakouts. Peters was an underslot seventh-round signing by the Brewers in 2021. He’s the second big leaguer this century to come out of Southern Illinois University Carbondale, joining Sam Coonrod. (Dave Stieb and Steve Finley also played college ball for the Salukis, so it’s not as though there haven’t been any big names to come from the program … it’s just been awhile.) He went to high school in Winkler, Manitoba — a town of just over 13,000 in western Canada. Prior to being drafted by the Brewers, Peters’ baseball claim to fame was probably playing for the Savannah Bananas.

Peters has never at any point ranked among Baseball America’s top 30 prospects for an organization that employs him. That includes the Brewers, the Giants, the Rays and now the White Sox. The 2022 Brewers traded Peters to the Giants in exchange for reliever Trevor Rosenthal at a time when Rosenthal hadn’t pitched since the 2022 season. Milwaukee ate the remainder of Rosenthal’s $4.5MM salary to pay a “lesser” prospect cost in the deal. Three months later, San Francisco traded Peters to Tampa Bay in exchange for utilityman Brett Wisely. Peters eventually made his major league debut with the Rays last season, tallying 12 hitless plate appearances in a late-season cup of coffee. The Rays designated Peters for assignment in December and traded him to the White Sox for cash.

That’s certainly not the career arc of a player who goes on to make the All-Star team as a rookie, but Peters did just that this past July. At the time, he was an injury replacement for A’s first baseman Nick Kurtz. Peters had only 275 plate appearances at the time he was added to the roster (287 in his career), making him a rather surprising selection. He struck out in his lone plate appearance against Dodgers southpaw Justin Wrobleski during the Midsummer Classic.

There was likely some skepticism among fans looking at the unexpected nature of Peters’ breakout and the sample in which he’d produced at an All-Star form. After all, 275 heavily platooned plate appearances don’t necessarily foreshadow a full-fledged breakout, and Peters was sitting on a middling 6.5% walk rate with a bloated .354 average on balls in play. However, Peters hasn’t slowed down much in the season’s unofficial second half. The output he’s produced has only further added some legitimacy to his status as a bona fide big leaguer.

In 182 “second-half” plate appearances, Peters is hitting .244/.330/.438. It’s a notable drop in each slash stat, but his 8.8% walk rate is actually an improvement and he’s hitting for more power on a rate basis (.194 ISO versus .177 in the first half). Peters had a brief slump for a few weeks but has caught fire of late; over his past 104 plate appearances he’s slashing .333/.404/.634. There’s some BABIP luck in there, but he’s walked at a nearly 8% clip against just a 14.4% strikeout rate — both notable improvements over his early-season form. He’s sitting on a hefty 46.2% hard-hit rate in that span.

It’s still fair to question the overall sustainability of Peters’ offensive production. He’s only averaging 87.5 mph off the bat with a 33.9% hard-hit rate. Neither mark is particularly close to the respective league averages of 88.5 mph and 38.6%. His contact rate on pitches within the strike zone is an exact match for the 86.1% league average. Peters makes contact at better-than-average rates when he chases off the plate, but he also chases more frequently than the average hitter. He’d be better served swinging a bit less frequently and running up his walk rate a bit further.

Then again, there are already some indicators of altering that approach. Peters chased off the plate at a 35% pace through the end of June. He’s since turned in monthly chase rates of 31.3%, 25% and 27.8%. We’re only two weeks into September, but he’s swung at 85% of pitches within the strike zone and made contact on an outstanding 90.3% of those swings. His walk rate this month is the lowest of any month this year, but that’s also due to the increased focus on swinging at the right pitches.

Where Peters isn’t likely to slump is on the defensive side of the game. Statcast credits him with 84th-percentile sprint speed but 96th percentile range due to his reads and jumps in center field. He has average arm strength, so he’s better suited for center and left field than right, but he can cover more than enough ground to sufficiently handle any of the three slots. Sports Info Solutions’ Fielding Bible credits Peters with eight runs saved due to his range this year, with his arm grading out a run below average. Overall, that leads to +7 Defensive Runs Saved. Statcast credits him with a hearty 11 Outs Above Average. Bear in mind, too, that his platoon issues mean those marks have come in less than a full season of innings; he’s at 1055 frames across all three outfield positions at the moment.

It’s too early to call Peters a perennial All-Star candidate. Even this year’s selection was arguably dubious, based on the limited number of plate appearances he carried into the break. He’s made some positive strides when it comes to his approach at the plate as the year has progressed, but we still haven’t seen him sustain those gains over a larger sample. There’s plenty of room for regression, particularly if he can’t find a way to make better contact and/or run up his walk rate.

However, Peters has shown that the plus hit tool he showed in the lower minors will carry to the majors. That, coupled with his speed and instincts on the grass, will give him enough floor to at least be a platoon regular, but Peters is still acclimating to the majors. If the incremental improvements he’s made in pitch selection can yield more walks and/or more power, future All-Star selections can’t be ruled out. And if nothing else, he’s gone from a DFA roll of the dice to looking like a legitimate member of his fourth team’s core.

If you’d told the White Sox and their fans entering the season that by year’s end, they’d be looking at an outfield comprised primarily of in-house development and one outside acquisition, most probably would’ve expected that outside addition to be Luisangel Acuña, whose acquisition in the Luis Robert Jr. trade hasn’t really borne any fruit. Maybe they’d have bought into an Andrew Benintendi rebound or assumed the Sox made a nice pickup at the trade deadline.

Few would’ve presumed that Peters, scooped out of DFA limbo and on his fourth team in six years, would have emerged into this type of potential core contributor. And yet, that’s where the Sox find themselves — reaping not only the short-term benefits but long-term value as well. Peters can still be controlled for five full seasons after the 2026 campaign. He won’t be eligible for arbitration until the 2028-29 offseason. The legend of “Banana Bonds” has plenty of time to grow on Chicago’s south side.