Under the Radar details players in the Chicago White Sox system who may have suffered setbacks, gotten lost in the shuffle, or just haven’t surfaced as significant prospects as of yet. Next up is Jordan Guerrero, a former top prospect whose inconsistencies have dropped him out of many top prospect lists.
Jordan Guerrero (LHSP) Charlotte Knights
Guerrero, a native of Oxnard, Ca., was drafted in the 15th round by the White Sox as a lanky, six-foot-three, 165-pound southpaw from Moorpark High School. His first two years were spent with Bristol, where he combined for a 3.93 ERA and 1.46 WHIP by allowing 41 hits (.301 OBA) and nine walks (6.2 BB%), while striking out 21 (14.5 K%) Appalachian League hitters over just 34 innings of work.
The spotlight started shining on Guerrero after a stellar 2014 with Kannapolis, in which he pitched in 27 games (nine starts) encompassing 78 innings. He enjoyed a 3.46 ERA and 1.38 WHIP, while allowing 81 hits (.266 OBA) and 27 walks (8.0 BB%) while striking out 80 (23.8 K%).
He began the 2015 season as the No. 28 White Sox prospect according to MLB Pipeline. He ascended to No. 9 in their midseason rankings after a successful campaign that year with Kannapolis and Winston-Salem, with a combined 3.08 ERA and 1.04 WHIP over 149 innings while allowing just 124 hits (.230 OBA) and 31 walks (5.3 BB%) while striking out 148 (25.1 K%).
Although he began the 2016 season as the White Sox No. 6 prospect, the wheels started falling off that year with Birmingham. Guerrero, normally the possessor of terrific control, walked more hitters that year (73) in 136 innings than he did in his previous three years (252 1⁄3 innings) combined. His walk rate increased to 12.2%, his punchout rate decreased to 18.1%, and his OBA increased to .260. As a result, his ERA and WHIP rose drastically, to 4.83 and 1.51 respectively. Due to a combination of his 2016 slump and the acquisition of several elite prospects, Guerrero dropped to No. 21 in the organization’s MLB Pipeline rankings.
He returned to Birmingham in 2017 with numbers that basically split his 2015 and 2016 results. For the Barons last year, he pitched his way to a 4.18 ERA and 1.32 WHIP over 146 1⁄3 innings while allowing 150 hits (.270 OBA) and 43 walks (7.0 BB%) while striking out 136 (22.1 K%). Despite the improvements, he fell off many prospect lists (including MLB Pipeline) and was left unprotected from last year’s Rule 5 draft, to the disgruntlement of Guerrero and many White Sox fans. However, he surprisingly went unclaimed.
The White Sox surprised many by leaving Guerrero, Spencer Adams, and Jordan Stephens in Birmingham to begin 2018. While Stephens excelled to start the year and was promoted relatively quickly, Adams and Guerrero both struggled out of the gate. Prior to his promotion on June 29, Guerrero has suffered through a rather unsightly season, with a 6.06 ERA and 1.58 ERA over 65 1⁄3 innings, allowing 84 hits (.315 OBA) and 19 walks (6.5 BB%) while striking out 58 (19.8 K%) Southern League hitters. A light switch seemed to turn on for Guerrero upon his promotion to Charlotte, as he pitched quite effectively despite working in a much more hitter-friendly ballpark. In his 65 innings for the Knights, his ERA and WHIP fell to 3.46 and 1.42 respectively after allowing just 64 hits (.251 OBA) and 28 walks (9.8 BB%) and inducing opponents to whiff 62 times (21.8 K%).
Guerrero, who is 24 and is now listed at 195 pounds, has a fastball that can run up to 94 according to FanGraphs, but typically runs in the lower 90s. His changeup is considered by most scouts to be his best pitch — some sites, like FanGraphs, grade it as 60. Guerrero gets in trouble sometimes by living exclusively with the change, which typically works best as a secondary pitch if there’s a big enough disparity between it and the fastball. A third pitch for Guerrero is a curveball, which is average at best, but has hittable slurvy action at its worst. His fourth pitch is a slider, which he’s deployed much more during the past couple of years. Over the course of his career, righties have only hit Guerrero slightly better than lefties; however, while his change works well against righties, Guerrero doesn’t have a consistent out pitch against lefties, as his slider and curve are still works in progress.
With only three starters locked into the rotation of the 2019 White Sox rotation (Carlos Rodon, Lucas Giolito, Reynaldo Lopez), Guerrero should be in the mix for the back end, depending upon offseason trades or free agent acquisitions. The White Sox likely will acquire at least one veteran to fill one of those spots. For the final spot, it could come down to Guerrero, Adams, or Stephens. All three of them are eligible for the Rule 5 Draft this year, so we may get a clue as to the White Sox’s preference once the protected lists come out.
As of right now, I’d give Stephens the nod because of his age; however, the battle to make it to the big leagues may largely depend upon who has the best spring training of the three. It may be difficult for Guerrero to crack the 2019 Opening Day roster as a reliever, since three other southpaws are near-locks to begin the season with the White Sox: Jace Fry, Aaron Bummer, and Caleb Frare. Based on his career minor league WHIP of 1.35 and ERA of 4.09, Guerrero’s ceiling is that of a back-end starter, while his floor is that of a long reliever. A reasonable comp is current Sox southpaw Hector Santiago, whom Guerrero could supplant as next year’s swing man/spot starter.