Jarlin Susana is wasting no time making noise in the Arizona Fall League.
The Nationals’ No. 4 prospect has been one of the loudest arms in the league this fall, and the headline number jumps off the page: he has already fired the 34 fastest pitches in the AFL this season, according to MLB.com. His heater has reached 103.8 mph, and all five of his hardest pitches have come in above 103.0 mph.
That kind of velocity would play anywhere. If Susana had been doing that during the 2026 MLB season, that 103.8 mph fastball would have ranked among the 40 fastest pitches in the majors this year.
More specifically, it would have made him the fifth-hardest thrower in MLB. The only pitchers ahead of him in that group were Jacob Misiorowski, Ben Joyce, Edgardo Henriquez and Mason Miller.
What makes it even more interesting is that Susana’s fastball isn’t even the pitch that gets the highest grade in his scouting report. On the 20-80 scale, his fastball sits at 60/65, while his slider is rated as his best pitch at 70/80. Fangraphs believes Susana could end up with one of the best sliders in baseball, while his fastball may top out at 65.
For the Nationals, this is an encouraging development from a pitcher who has already had to fight his way back. Susana tore his lat muscle in 2025 and missed nearly a full calendar year.
He did not return to minor league baseball until August, then appeared in only eight games in 2026. Even so, he showed plenty in the Triple-A Championship game, where his velocity stood out.
The Arizona Fall League is built for situations like this. It gives prospects extra at-bats or innings after the minor league season, with six teams made up of select players from around MiLB. For someone in Susana’s position, those extra reps matter even more.
He is also the only top-100 pitching prospect in the league this fall, which makes his numbers stand out all the more. Talent level may be lower across the AFL, but Susana has not looked like a player just filling innings. The stuff is real, and the radar gun keeps backing it up.
Susana is scheduled to make his MLB debut in 2027, and he has a legitimate chance to crack the Opening Day roster.
In Other News...
Nationals Just Lost A Hitting Voice Other Teams Clearly Wanted
CJ Gillman is on the move after a season in Washington, where he worked as the Nationals director of hitting before the Mariners moved to bring him in as their new hitting coach. For Seattle, the hire adds an internal voice it already knew well from his time as the clubs minor league hitting coordinator, and it comes amid a broader staff shake-up that began with the departure of former hitting coach Kevin Seitzer.
For the Nationals, it is another reminder that the organization has people around the league paying attention to its player-development work. Gillman leaving for a division rivals staff is the kind of move that can sting a bit because it suggests other teams see value in the approach Washington had in place. It also underscores how quickly the coaching market can shift, with Seattle making its first appointment even before naming a new manager. [Read more 🡒]