Arizona Fall League Preview: Miami Marlins
By Eric Simmons ·
Eight Marlins join the Glendale Desert Dogs for the 2026 Arizona Fall League, and two themes run through the group: players making up time lost to injury, and pitchers looking for a cleaner version of what they showed in the regular season. 80Grade's Prospect Rank has Dillon Lewis 27th in the Marlins system, Carter Johnson 32nd and Max Williams 55th, but Williams has a legitimate case as one of the more interesting offensive performers in the AFL field.
Max Williams Torched Three Levels and Still Has Something to Prove
Max Williams is the most compelling Marlin in Glendale, and his 2026 numbers are not subtle. Activated from the injured list on July 9 after February surgery to repair a torn labrum in his left (throwing) shoulder, the 22-year-old hit .326/.399/.620 with 15 home runs in 48 games across three levels, with a 10.3 percent walk rate and a 16.4 percent strikeout rate. He went 20-for-58 (.345/.465/.534) at Single-A Jupiter and 29-for-95 (.305/.353/.568) with seven homers at High-A Beloit, then produced his most jaw-dropping line at Double-A Pensacola: 12-for-34 with six home runs, a .353/.400/.912 slash and three strikeouts in 40 plate appearances.
That nine-game Double-A sample is too small to lean on, but contact quality runs through all three stops. His 70.6 percent contact rate is respectable for a hitter who swings 52 percent of the time, and that aggressive posture usually costs walks. Williams walked at a 10.3 percent clip anyway, which suggests he is hunting fastballs in the zone rather than chasing.
Marlins director of player development Rachel Balkovec told MLB.com that Williams and Lewis both "missed a bunch of time," and the fall is about making it up. 80Grade's scouting profile projects Williams to left field rather than center, so the desert is a chance to show he can handle a full outfield workload again. The bat is ahead of where anyone could have expected after shoulder surgery, and a longer body of work will show how much of it holds up.
Dillon Lewis: Power-Speed Threat in a Make-Up Stint
Lewis came over from the Yankees in the January trade for Ryan Weathers, then landed on the injured list in late June with a broken hamate bone and missed about seven weeks. In 89 games at Double-A Pensacola, he hit .242/.302/.460 with 18 home runs, 20 stolen bases and a 30.2 percent strikeout rate.
That power-speed combination at 23 is the profile's carrying element, and 18 homers with 20 steals in fewer than 90 Double-A games is production, not a paper line. The concerns are just as clear. His 67 percent contact rate against a 46.3 percent swing rate traces back to a long, leveraged stroke that pitchers can attack with velocity up and breaking balls away. His 7.6 percent walk rate sits just below average, and his strikeout rate jumped from 23.5 percent across two Class A levels in 2025. 80Grade's projection of a left-field bench or quad-A outcome reflects those risks.
If Lewis can improve his two-strike approach and hold the strikeout rate closer to 25 percent against advanced arms this fall, the power and speed push his floor up considerably. For now, the swing-and-miss limits how much of the power plays.
Carter Johnson Working Through a Real Challenge
Johnson, 20, is still early in a difficult professional adjustment. A 2024 second-round pick out of high school with a reputation as an elite contact hitter, he struck out 28 percent of the time at Single-A Jupiter and 24.3 percent after a midseason promotion to High-A Beloit, where his walk rate fell from 13.8 percent to 7.5 percent. The promotion exposed a pitch-recognition gap, and recognizing breaking balls remains the central hurdle in his scouting report.
The combined line (.240/.335/.410, 14 home runs, 14 stolen bases, 25 doubles) has positive pieces, and he held his own at a level most 20-year-olds are still working toward. His 71.9 percent contact rate on a 46.8 percent swing rate is roughly league average, which is not alarming at his age.
Balkovec framed the stint as more at-bats against competition that matches what Johnson needs, and she credited him with buying into training his weaknesses this year. The 80Grade profile keeps him at shortstop with a solid-average arm, though it questions whether he has the range to stay there long term, which puts even more weight on the bat.
The Pitching Group: Alex Williams, Emmett Olson, and the Command Questions
Alex Williams, 26, made 18 starts at Pensacola and posted a 5.78 ERA across 85.2 innings. His 23.1 percent strikeout rate is workable for a rotation piece; the 10.6 percent walk rate and 13 home runs allowed are the problem. A 29.2 percent whiff rate says the stuff can miss bats, so if the walks come down against good hitters this fall, the command issue looks addressable. He missed about a month in midseason, and 80Grade has no scouting profile on him, so the evaluation stops at the stat line.
Emmett Olson, 24, had one of the more turbulent seasons in the group. Coming back from Tommy John surgery in 2025, he made two rehab starts at Jupiter (five innings, two earned runs), then posted a 13.03 ERA in four High-A starts and walked seven in 3.1 innings in his one Double-A start. Across the three levels he walked 20.4 percent of hitters and threw 52.9 percent of his pitches for strikes, the numbers of a pitcher still searching for his release point after surgery. 80Grade's report, written before his return, calls his above-average curveball his best pitch, pairs it with an average changeup and credits a repeatable tall-and-fall delivery. The back-end starter he looked like before surgery remains the target.
Brayan Mendoza, 22, is a left-hander whose best pitch is a changeup that 80Grade grades at 55. He posted a 5.89 ERA over 94.2 innings at High-A, with a 24 percent strikeout rate, an 11.4 percent walk rate and a 26.4 percent whiff rate. A fastball that sits around 89 mph and tops out near 91 limits his ceiling as a starter, and the Marlins used him in a hybrid role (12 starts in 30 appearances). His walk rate barely moved from 2025, so the desert is another chance to find the command he needs.
Round-Up: Carpio and Stevens
Samuel Carpio, 23, pitched out of the bullpen all season at Single-A Jupiter and walked 60 batters in 60 innings, a 21.1 percent walk rate. He gets whiffs on 34.6 percent of swings, but the control has to improve before that swing-and-miss can play in higher-leverage spots, and the AFL assignment is built around exactly that.
Tristan Stevens, 28, is the oldest player in the Marlins' group and had not pitched in a game since April 2025 before returning this August. He threw 15.2 innings across 10 games between Jupiter and Pensacola, allowing four runs with a 0.83 WHIP and a 7.3 percent walk rate. The AFL is about building innings and confirming the arm is durable. At 28, there is little developmental runway left beyond getting healthy and performing.
Bottom Line
Max Williams is the Marlin whose fall carries the most weight. He compressed three levels into 48 games after shoulder surgery, and the AFL is where he can answer the defensive questions and show the contact quality holds against pitchers who have seen him on film. If the bat and the shoulder both hold, his timeline to Miami could speed up considerably. Everything else in Glendale is useful organizational work, but Williams is the name to follow this fall.