GLENDALE, Ariz. – One reason why teams send players to the Arizona Fall League is because a decision has to be made about putting them on the 40-man roster or leaving them exposed to December’s Rule 5 Draft. This last stretch of performances, and how a player responds to the pressure of knowing a call on a roster spot is looming, can change an organization’s decision.

Reds reliever Luis Mey was one of the many players sent to Arizona this fall for exactly that reason. Signed for just $50,000 at the start of the 2018-19 international signing period, the 6-foot-5 right-hander has long brought an intriguing combination of size and power stuff to the mound. He has struck out 9.8 per nine innings in his Minor League career, and 10.3/9 during a 2024 season in which he reached Double-A for the first time.

Along with that, though, has come a career 7.1 BB/9 rate, which made it very unclear whether Mey would land on Cincinnati’s 40-man roster this offseason. But much like he did in recording his fifth save of the fall for Glendale on Friday, Mey has slammed the door on any doubt. It’s hard to imagine the Reds would leave him exposed in the Rule 5 and it’s easy to envision him pitching out of their Major League bullpen at some point in 2025. So he used the roster potential to motivate and fuel his performances this fall, right?

“No,” Mey said, making it very clear that calculus never entered his head. “They gave me the opportunity and I was going to go there and show while I’m here and just keep doing what I know I have to do.”

What he’s done is be the most dominant reliever in the Fall League. After his perfect ninth to finish the Desert Dogs’ 5-2 win over Mesa, he’s thrown 6 2/3 hitless innings over six appearances. The 23-year-old has racked up eight strikeouts, and most surprisingly, walked just one while hitting one batter. While his 2024 regular-season numbers don’t reflect it, Mey said his success here comes from the effort he’s put in all year to improve the one part of the game that could keep him from finding high-leverage innings in the big leagues.

“It is,” Mey said when asked if this is the best he’s ever pitched in his career. “I’ve been working hard in my approach. This [fall], it’s just showing up that the work is paying back now.”

Friday's appearance showed just how much he’s matured and been able to stick to that approach. He fell behind Tre’ Morgan 2-1 and again 3-2, but struck out the Rays' No. 10 prospect on a 100-mph sinker for the first out of the ninth. Down 2-0 against Moises Ballesteros (CHC No. 4/MLB No. 44), he got one of the better hitting prospects in the game on a routine fly ball to left field off a 98-mph sinker. Down 2-0 against Jonathan Long (CHC No. 30), Mey went sinker (98 mph), sinker (99.7 mph) and slider (84.6) to get him swinging to end the game. The Dominican Republic native's issues with the zone have never been physical or mechanical in nature. He knows it’s all in his head.

“It’s a mental thing,” Mey said. “It doesn’t matter if I get 2-0, like today, just keep pounding the zone, it will be a good outcome after that. I just have to live with it. The walks will be there forever because it’s part of the game, but don’t focus on it and keep throwing strikes.”

The Reds have certainly sat up and noticed.

“He’s risen to the challenges of late,” Cincinnati farm director Jeremy Farrell said. “He’s been more consistent and competitive in the strike zone and is attacking good hitters with success. With his presence on the mound and the way the ball comes out of his hand, the ability is there. He seems to be gaining confidence and it’s been fun to watch.”

It’s not often that a pitcher establishes himself as a closer in the Fall League because there are so many arms who need innings out of the bullpen. No reliever has had more than Mey’s five saves for an entire Fall League season since Carlos Estévez posted six in 2015. Perhaps a harbinger of things to come, Estévez was added to the Rockies’ 40-man roster to protect him from the Rule 5 Draft after his AFL performance, and he’s gone on to be an All-Star closer with 57 saves over the past two years. It’s a path Mey hopes he can be on as well.

“It’s super cool, knowing you’re going to be in this kind of situation,” Mey said about closing games out this fall. “I’m open to get this spotlight everywhere. That’s my dream. I want to be just like Aroldis Chapman, but he’s lefty. I’m going to be my own kind. I’m going to be like Luis Mey for [a long] time.”

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Mey likes watching Chapman because they both throw a sinker-slider combination, and he likes watching Guardians closer Emmanuel Clase -- who throws cutters -- because of his mental approach. It may take some time for Mey to keep growing into that kind of role, so no decision has to be made now, but the one thing he hasn’t contemplated is what will be blaring over the loudspeakers when the bullpen gate opens some day in a big league ninth inning.

“My walk-out song? I never thought about it before,” Mey said. “It will be something cool when I get there.”