Southside Prospect Weekly: Zavala's September Plate Discipline Peaks, Murphy Rolls at Charlotte
By Gordon Kairis ·
Southside Prospect Weekly covers the last 7 days of action for the White Sox farm system.
Zavala's September Patience Reaches Another Level
Samuel Zavala (AA, CF, Rank: 15) went 4-for-12 with two home runs, a double, 7 RBI, and four walks across 12 plate appearances at Birmingham this week, a line that doubles as a microcosm of what he has been doing all month. The two home runs are the eye-catcher, but the plate discipline is the real story. Over the last 30 days at Double-A, Zavala owns a 37.0 percent walk rate across 73 plate appearances, which is a genuinely absurd number for any level of professional baseball. He has 27 walks against just 10 strikeouts in that span, his swing rate has dropped to 32.1 percent, and the contact rate has actually ticked up slightly to 72.3 percent. Pitchers are struggling to put him away, and increasingly they are not trying.
The broader season context matters here. Zavala's full-year line at Birmingham sits at .235/.390/.389 with 14 home runs and a 19.4 percent walk rate across 484 plate appearances, which reads like the profile: a left-handed bat whose on-base skills consistently outpace his batting average, with emerging pop that was not a certainty coming into the year. He drew 65 walks in 500 plate appearances at the same 37.8 percent swing rate last year at High-A, so the approach is not new, but the September home run production is a meaningful addition. He is a 45 hit, 45 power bat who profiles best in left field, with an up-down or fourth-outfield projection. The two-homer, four-walk week does not rewrite that profile, but a month in which he is posting a .603 on-base mark and going deep twice gives the power grade a nudge worth tracking as he heads into the offseason.
Murphy's September Is Making Charlotte's Rotation Look Good
Shane Murphy (AAA, LHP, Rank: 42) worked 11.1 innings across two appearances this week, allowing 2 earned runs on 8 hits with 2 walks and 7 strikeouts. That is a workload and a quality line from a pitcher whose full-season AAA numbers have been a grind: a 5.13 ERA across 93 innings at Charlotte with 26 home runs allowed. September has been a different story entirely. Over the last 30 days, Murphy has posted a 1.21 ERA in 29.2 AAA innings with just 5 walks against 21 strikeouts and a 4.3 percent walk rate that represents the best command stretch of his Triple-A season. His pitches-per-inning rate over that span sits at 13.5, which is a genuinely efficient number and well below the 18-plus threshold that has dogged parts of his 2026 campaign.
Murphy's profile is built on a 55 command grade doing the heavy lifting for a stuff mix that does not scare anyone on paper. The four-seamer sits 90-92, the cutter and slider are both 45-grade offerings, and the curveball at 78 mph is his best shape-changer. At Birmingham last year he was dominant despite that modest arsenal, posting a 1.38 ERA across 110 innings with a 3.7 percent walk rate. The jump to Charlotte exposed what everyone expected it would: hitters who can spit on the slider and wait for the fastball to drift. The 26 home runs allowed at Triple-A this season tell that story clearly. But when Murphy is throwing his curveball for strikes and working his two-seamer to the edges, the sequencing works even at this level, and September is the proof. The projection remains a long reliever or depth starter at the big-league level with a realistic quad-A outcome, but a month with a sub-1.30 ERA at Triple-A is the version of Murphy that keeps his name in organizational conversations going into 2027.
Quick Hits
- Caleb Bonemer (AA, 3B, Rank: 2) · went 3-for-13 with a home run, a walk, and 4 strikeouts across 13 plate appearances at Birmingham. A modest counting line, but his 19th homer of the year lands in the context of a 30-day stretch in which he has slugged at a .552 clip with 7 home runs in 105 plate appearances. Bonemer has 37 combined home runs across Double-A and High-A this season at age 20, sitting on a 60 power grade with a 50 hit tool and true everyday projection. The season-long 27.1 percent strikeout rate is the main friction point in an otherwise advanced offensive profile, but the production has not slowed despite the move to Birmingham. I would take the over on his current grades if the swing refinement continues.
- Ryan Burrowes (AA, SS, Rank: 17) · went 5-for-12 with a double, a triple, and 2 strikeouts across 12 plate appearances this week at Birmingham. No walks, but five hits on 12 at-bats from a 22-year-old shortstop with 45 steal attempts on the year is a line that keeps his utility ceiling alive. His season at Double-A sits at a .245/.335/.317 clip in 162 plate appearances, a meaningful step down from his .261/.379/.421 line at High-A to start the year. The gap between levels is real, and the bat will need to tighten against better velocity and spin to hold the shortstop projection. The 45 speed, athleticism, and baserunning value keep him relevant regardless.
- Dylan Campbell (AA, CF, Rank: 36) · went 2-for-10 at Birmingham with a home run, 3 walks, and 2 strikeouts across 13 plate appearances. The 12.4 percent walk rate over his last 30 days at Double-A represents a genuine improvement over the 8.3 percent he posted at Reading earlier this season, and his 37 stolen bases on the year continue to make him interesting as a depth piece. He is a 60 speed, 55 arm profile with a 40 hit tool projection, so the bench or fourth-outfield ceiling is real; the bat just needs to hold well enough to make the glove and legs matter regularly.
- Grant Umberger (A+, LHP, Rank: 44) · threw 7.1 innings this week, allowing 0 earned runs on 3 hits with 3 walks and 11 strikeouts. A strong week on its own, and it fits a September run that has been his best stretch of the season: a 2.73 ERA over 29.2 innings in his last five outings, with a 33.3 percent strikeout rate and a 4.3 percent walk rate that is a significant improvement over his season-long 7.4 percent mark. The full-year ERA sits at 4.70 through 120.2 innings at High-A, with 17 home runs allowed dragging the number up. When his command is this precise, the five-pitch left-handed arsenal profiles like a back-end starter. The question is how often he can string these outings together.
- David Sandlin (MLB, RHP, Rank: 11) · was recalled by Chicago on September 13, his third big-league stint of the season. His AAA ERA sits at 2.22 across 65 innings at Charlotte before the call, a number that continues to be his most reliable indicator. The big-league results have been rougher, a 5.64 ERA across 30.1 innings in six appearances this year. He carries a power four-seamer in the upper-90s and a hard slider that generates volume whiffs at Triple-A; the command variance is what makes the major league results inconsistent. September roster expansion gives him more chances to work through it at the highest level.
- Ely Brown (A+, OF, Rank: 43) · was placed on the 7-day injured list by Winston-Salem on September 15. No diagnosis has been confirmed. He last appeared on September 13, and his season line at High-A sits at .275/.399/.372 with 5 home runs and 26 stolen bases across 539 plate appearances, a productive full-season effort for a depth outfielder. A late IL stint is not ideal heading into the offseason, though the injury details remain unclear.