South Capitol Nats Prospect Weekly: Wallace's September Surge, Susana's Rocky Triple-A Debut
By Marcus Bailey ·
South Capitol Nats Prospect Weekly covers the last 7 days of action for the Nationals farm system.
Wallace Is Locked In at Rochester
Cayden Wallace (AAA, 3B, Rank: 42) delivered his best week of the season, going 8-for-27 with four doubles and eight RBI across his Rochester games. The week fits neatly into a September run that has been the most productive stretch of his professional career. Over his last 30 days at Triple-A, he is slashing .375/.445/.667 with six home runs, ten doubles, and 28 RBI across 110 plate appearances, with a 10.0 percent walk rate and a contact rate of 78.1 percent. That is a different player than the one who posted a .242/.310/.376 line across 481 plate appearances at Double-A Harrisburg in 2025, and the gap is too wide to explain away as variance alone.
The underlying profile makes the surge legible. A compact, quick-handed swing has always been his best tool, and that swing plays when his timing is on, as it clearly has been for a month straight. His aggressive 52.6 percent swing rate over the last 30 days has not hurt him because the contact rate has held above 78 percent, meaning the aggression is translating to barrels rather than weak contact or empty swings. His 60 arm grade remains a genuine carrying element defensively. For the season combined across Double-A and Triple-A, he is at .303/.357/.549 with 29 home runs and 93 RBI in 558 plate appearances, numbers that make the utility-bench projection feel like a floor rather than a destination. The profile still carries real questions about whether an aggressive approach holds up against the best sequencing, and the defensive fringiness at third base is real. Still, what he has done over the past month in Rochester makes the argument for a second-division regular at the hot corner considerably easier than it was a year ago.
Susana Gets a Rough Welcome to Rochester
Jarlin Susana (AAA, RHP, Rank: 8) was promoted from Double-A Harrisburg to Rochester on September 15, becoming the youngest pitcher in the Nationals system to reach Triple-A this season. The debut did not go well. He lasted just 2.2 innings against 16 batters, allowing four hits and four earned runs on four walks, with three strikeouts and only five swinging misses on 66 pitches. He threw 29 of those 66 for strikes, a 43.9 percent rate that encapsulates the central challenge in his development: a fastball that sits 99-103 mph and a slider and sweeper that each grade at 65 are not producing results when fewer than half the pitches thrown find the strike zone.
The command concern is not new. His 40 command grade is the loudest flag in the profile, and the season numbers make it concrete: a 25.0 percent walk rate in his Triple-A debut, an 11.7 percent walk rate across all levels combined, and a pitch efficiency of 18.7 P/IP for the season that reflects deep counts that make multi-inning starter work unsustainable. At Double-A over the last 30 days before the promotion, his ERA sat at 5.40 across 16.2 innings, so the stuff was not exactly dominating at the lower level either. The projection here is a setup reliever with an all-star ceiling, and the case for the bullpen grows stronger every time a start looks like this one. In short stints, the 99-103 mph four-seamer and the sharp slider get to operate without the accumulated pitch-count pressure that reveals the command gaps. His Triple-A debut was rough, but the stuff that grades 65 or better on three separate pitches remains as real as ever; the path to unlocking it probably runs through a one-inning role rather than a rotation slot.
Quick Hits
Seaver King (AAA, SS, Rank: 4) · had a modest week at Rochester, going 7-for-31 with two doubles, a home run, three RBI, two walks, and six strikeouts. The homer was his 20th of the season, a milestone that lands in a genuinely strong year: a combined .302/.380/.511 slash across Double-A and Triple-A with 20 home runs, 15 stolen bases, and a 9.5 percent walk rate in 515 plate appearances. His last 30 days at Rochester have been slower, though, with a 24.4 percent strikeout rate and a 66.4 percent contact rate over 123 plate appearances, and the swing-and-miss has ticked up at a level where advanced arms can probe his tendency to lengthen when looking for damage. The season as a whole is a clear step forward from the .233/.287/.313 he posted at Double-A in 2025, and the 20th homer is a real marker. A second-division regular projection with shortstop value still fits the body of work; the question heading into the offseason is whether the late-season contact dip is fatigue or a sharper look from Triple-A pitchers.
Andrew Pinckney (AAA, LF, Rank: 28) · was optioned from Washington back to Rochester on September 17. He played sporadically, tallying 29 Major League plate appearances in 17 games. He managed to hit .280 in those appearances, but struck out 10 times.
Caleb Lomavita (AA, C, Rank: 27) · was transferred from the 7-day to the 60-day injured list at Harrisburg on September 13, effectively ending his 2026 season. No injury diagnosis has been confirmed publicly.