JUPITER, Fla. -- A former college basketball player years ago in his native Oregon, Cardinals relief pitcher Keynan Middleton still somewhat thinks of himself as a basketball player who plays baseball. While a brash and edgy persona brought over from his basketball days helps to fuel his fire on the mound, shedding some of that bravado just might have been a career-altering moment for the 30-year-old right-hander.

For years, Middleton has had one of the game’s most electric fastballs -- one that averaged 97.1 mph in 2020, regularly came in at 96.9 mph in 2017 and was clocked at 95.9 mph on average in 2023, per Baseball Savant. However, it wasn’t until Middleton learned to lean more on his changeup that he found the sort of success he’s sought for years.

Last season, while splitting time with the White Sox and Yankees, Middleton threw his changeup at 42.9 percent of the time -- up dramatically from the 17 percent usage he had with that pitch in 2022.

While he laughed at his changeup being comparable to that of Brewers All-Star closer Devin Williams, Middleton did limit hitters to a .209 average last season with the off-speed pitch. He did well with the fastball, as well (.122 average), but the improved movement and deception created by the changeup helped him keep hitters off-balance better.

“I think it’s deception," Middleton said. "It comes out of a weird arm slot and it has a little bit of movement. Last year, people weren’t really expecting it. This year, they’ll be expecting it a little more, but I’ve got a wrinkle for them.”

The Cardinals liked what they saw from Middleton so much that they rewarded him with a $6 million guarantee for 2024, and that contract can grow to as much as $11 million if the club picks up its option for 2025. That was enough for the Cardinals to poach Middleton from the Yankees, who saw the reliever post an impressive 1.88 ERA with 17 strikeouts in 14 1/3 innings with New York late last season in 12 appearances.

Manager Oliver Marmol feels that Middleton has good enough stuff and the fearlessness to be an effective setup man.

“I love his personality, he’s got an edge to him, he’s a competitor and he’s all about winning,” Marmol said. “You can sense that seconds into a conversation. He’s going to be a nice fit for us.”

Middleton was shrouded in controversy for a period of time last season when he publicly questioned the team rules structure and the lack of accountability among White Sox players. New Cardinals hurler Lance Lynn, who played with Middleton in Chicago, backed up his teammate at the time, telling the Chicago media, “He’s not wrong.”

Marmol made the first step of getting to know Middleton on a personal level by inviting the reliever to his home in suburban St. Louis after his physical was complete. While there, Middleton met Marmol’s wife, Amber, and his two daughters and they shared a meal before talking baseball strategy and life.

“That was the first time I’ve ever done anything like that,” Middleton said of the family dinner at the Marmol household. “To be able to sit down at the table, break bread and talk to him and his family, that was great. That made me very excited to know that we’re very like-minded.”

While Middleton and the Cardinals are like-minded in how they are viewing his role this season, the reliever isn’t always the most well-liked person when he’s on the mound. And that’s just the way he likes it. In some ways, he sees the pitcher-hitter battles as comparable to one-on-one matchups in basketball when he played at Lane Community College in Eugene, Ore.

“I’m the nicest guy in the world when I’m walking around [the clubhouse], but when I get between those lines, I’m definitely a different person,” he said.

The Cardinals think Middleton has the kind of pitch arsenal, advanced metrics and demeanor that could potentially make him a high-leverage reliever at times late in games. Last season, he ranked in baseball’s top 3 percent in allowing the lowest exit velocity (85.3 mph), per Baseball Savant. He was also in the top 9 percent in strikeout rate (30.2 percent) and the top 8 percent for the lowest hard-hit rate (31.5 percent).

Said Marmol: “I think there’s room to see another level of what he’s doing. When you talk to him, he’s a huge basketball guy, grew up playing basketball and loves the game. But he isn’t fully developed [in baseball] from a physical and mental standpoint of how he approaches hitters. I think there’s room there. That’s exciting when you have his firepower with room for better understanding of how to attack hitters.”