The Reds have optioned former All-Star closer Alexis Diaz to Triple-A Louisville, per a team announcement. Fellow right-hander Luis Mey is being recalled from Louisville in his place. Mey will be making his MLB debut the first time he takes the mound.
It’s been a brutal season for Diaz, who already lost the closer’s role in Cincinnati. The 28-year-old righty opened the year on the 15-day injured list due to a hamstring strain. He returned a couple weeks ago but has been pitching with a career-low 93 mph average fastball velocity. He currently has more walks (five) and home runs allowed (four) than strikeouts (three). The result is a ghastly 12.00 ERA, which was inflated heavily by yesterday’s five-run meltdown against the Cardinals.
Diaz’s decline hasn’t been completely out of the blue. He was an excellent high-leverage arm in his first two seasons from 2022-23, finishing fifth in ’22 NL Rookie of the Year voting and making the ’23 All-Star team at the midpoint of a 37-save season. His 2024 campaign, however, was rife with red flags.
Last year’s 3.99 ERA wasn’t necessarily a harbinger for significant decline in and of itself, but Diaz’s average heater dropped from 95.2 mph in 2022-23 to 93.9 mph in 2024. His strikeout rate, which had topped 30% in each of his first two seasons, fell to a pedestrian 22.7%. His swinging-strike rate checked in at just 11% last year after sitting at a gaudy 15.6% over the two prior seasons. Diaz has never had good command, walking more than 12% of his opponents even at his peak, which makes the precipitous decline in his ability to miss bats all the more problematic.
Diaz hasn’t altered his pitch selection over the course of his career — he’s still a pure four-seam/slider reliever — but the shape, velocity and quality of his pitches have all gone the wrong direction. Beyond the drop in fastball velocity, his slider has actually gained a bit less than a mile per hour. What was once a nearly 9 mph gap between his heater and his slider is down to 5.7 mph at the moment. He’s also seen that slider lose a significant amount of its horizontal break; back in 2022, Statcast measured both the vertical and horizontal break of Diaz’s slider to be well above average. They’re both more than two inches worse than average now, and the whiff rate on the pitch has plummeted from 45% in ’22 to just 13% so far in ’25.
The Reds could’ve non-tendered Diaz over the winter, but they kept him around and agreed to a $4.5MM salary for the current season. Depending on the length of this optional assignment, the demotion could push the right-hander’s path to free agency back by a year. He entered the season with exactly three years of MLB service, and if he spends more than two weeks in Louisville, he won’t accrue a full year this season. That’d push his free agency back from the 2027-28 offseason to the 2028-29 offseason.
Of course, that’ll only come into play if Diaz is able to restore some of his prior form. If he continues to struggle anywhere close to this level, he’ll be a non-tender candidate in November or perhaps even a DFA candidate between now and season’s end. For the time being, he’ll look to get back on track in Triple-A.
Turning to the 23-year-old Mey, he’ll add a flamethrowing arm to Terry Francona’s bullpen — but one whose command troubles aren’t all that dissimilar from those of Diaz. Mey is averaging a colossal 99.1 mph on his power sinker this year, but he’s walked at least 15.6% of his opponents in each of his four years of full-season ball in the minors. He doled free passes at a grisly 17.6% clip in 55 innings between High-A and Double-A last year, and he’s walked 16.7% of his opponents in nine Triple-A frames in 2025.
The glut of walks hasn’t necessarily been offset by prominent strikeout rates. Mey has been average or better in that regard throughout his career but has never really climbed into plus range. His strikeout rate has hovered between 23% and 28% from year to year, settling at a collective 25.9% rate dating back to 2021. Similarly, his sinker has produced strong but not quite elite ground-ball rates as he’s climbed the minor league ladder. He clocked in at 52% there in 2024 and has a 54.2% grounder rate so far in 2025.
The sheer power of Mey’s sinker, coupled with a slider that’s drawn anywhere from above-average to plus grades on scouting reports, gives Mey the foundation of a potentially dominant reliever. He’ll need to substantially improve upon his command in order to reach that ceiling, but he’s an intriguing arm for the Reds to take a look at in place of their newly demoted closer. Mey will presumably slot into low-leverage situations to start out his big league career.
