Jonathan Clark’s journey to the South Side Sox prospect system defies conventional scouting wisdom. Signed as an undrafted free agent on February 12, 2025, more than two years after his college eligibility expired, Clark entered the organization with little professional pedigree. His stint in the independent Pioneer League with the Glacier Range Riders and Missoula PaddleHeads yielded an 8.68 ERA over 25 games, leading many to question his viability beyond semipro ball. However, Clark’s decision to partner with Tread Athletics to retool his arm motion and increase flexibility proved pivotal. This mechanical overhaul transformed his delivery, allowing the 26-year-old right-hander to transition from a struggling starter into a reliable relief arm.
From undrafted free agent to AA standout, the right-hander’s mechanical overhaul pays off.
The results of Clark’s transformation are evident in his 2026 campaign, where he has established himself as a high-leverage option for Birmingham. Posting a 3.99 ERA and a 1.404 WHIP across 57 games, Clark has demonstrated the consistency required for the next level. His strikeout rate of 70 against 33 walks showcases improved command and velocity control, while his 9-3 record and nine saves highlight his effectiveness in high-pressure situations. With a 1.0 WAR, Clark has generated tangible value, ranking 16th among all right-handed relievers in the South Side Sox system. His age relative to his high level (+1.4 years) suggests he is developing on a realistic timeline for a late-blooming reliever.
Looking ahead to the 2027 season, Clark’s trajectory positions him as a significant piece of the White Sox’ bullpen infrastructure. As the 52nd-ranked prospect in the 2026 South Side Sox Top 100, his climb to No. 91 in the 2027 rankings reflects both the depth of the organization and Clark’s sustained improvement. For a player who was nearly overlooked by major league scouts, Clark’s ability to adapt and thrive in Double-A represents a successful investment in player development. His path serves as a case study for the value of mechanical adjustments and the potential hidden in undrafted talent.
Source: Yahoo Sports
