Blake Treinen was just learning how to walk when he almost lost his right thumb.
When he was about 2 years old, Treinen cut that thumb on glass, and his uncle held it together on the way to the hospital before he underwent extensive surgery. Treinen saved his thumb, but it had limited range of motion after the procedure. However, that injury turned into a blessing when he started playing baseball.
Treinen practiced throwing two-seam fastballs with Roger Clemens and Pedro Martinez training baseballs, which featured fingerprints to signal where the user should place their fingers. But the right-hander noticed he wasn't throwing it like his idols.
Treinen's thumb was a little higher on the side since he couldn't fully place it on the ball, creating a sinking motion on his pitches. That sinker became one of his best pitches as a youngster, and it still is to this day.
Led by his sinker, Treinen become a reliable Major League reliever after not receiving any Division I scholarship offers out of high school. He's been inconsistent this season, but he'll likely rely on his sinker to return to form after the Nationals traded him to the Athletics, the team he began his Major League career with.
"I think a change of scenery always feels like a fresh start," Treinen said after joining the A's on Monday. "It can definitely change an outlook on a season. There were some struggles over in D.C. performance-wise, but stuff-wise, I feel I'm still there."
Treinen didn't develop a strong sinking motion on his pitches until joining the Minor Leagues despite the natural sink on his two-seam fastball. As a starter at South Dakota State University, Treinen relied on his fastball and slider.
But Treinen practiced the pitch more when the Athletics selected him in the seventh round of the 2011 Draft, and his coaches and teammates noticed his sinking motion was better than most rookies -- let alone some Major League relievers. While most pitchers throw their two-seam with two fingers in the middle of the ball, Treinen tilts his fingers, which helps create the movement.
"I became who I was with it," Treinen said of his thumb. "It was a God-given ability."
Treinen exhibited his sinker when he made it to the Major Leagues with the Nationals in 2014 (he was traded from the Athletics in 2013), and even Ritchie Price, Treinen's college coach, was astonished. Price compared the motion of Treinen's sinker to Mariano Rivera's cutter, arguably one of the most remarkable pitches of all time.
Before Spring Training this year, Treinen visited the University of Kansas, where Price now coaches, and Treinen put the college players in awe while showcasing his sinker. The catcher of that bullpen session left with a swollen thumb.
"If anybody can learn to throw a ball that moves that much," Price said, "everybody would do it."
In his first three seasons with the Nationals, Treinen posted ERAs of 2.49, 3.86 and 2.28. Videos circulated online of his upper-90-mph sinker, which at its best moves right when the ball crosses the plate.
But Treinen struggled when he was placed in the closer role to begin this campaign. The 6-foot-5, 225-pound reliever was 3-for-5 in save opportunities, and had inconsistent command, notching a 5.73 ERA.
Treinen is hurling his sinker at an average of 96.8 mph this season, an increase from 96.1 mph last year, but he's not throwing it as much, and it's been less effective.
In 2015 and '16, Treinen threw his sinker 62.08 and 63.77 percent of the time, respectively, per Statcast™. This year, the 29-year-old has used it just 53.44 percent of the time.
Hitters have a higher expected batting average off Treinen's sinker this year (.281), according to Statcast™, compared to .245 in 2016 and .251 in '15. In turn, batters are knocking his sinker with more power, with a 2.6 percent increase in average exit velocity from last season.
"He's got great stuff, probably the best stuff on the team," Nationals pitcher Joe Ross said last month. "So to even see him get hit sometimes, I'm pretty surprised."
The Nationals wanted more dependable and experienced relievers to become stronger playoff contenders, so they traded Treinen and two prospects to the Athletics for Sean Doolittle and Ryan Madson on Sunday.
Now, Treinen will have a chance to resurrect his season and prove himself as a steady setup man in the same place he polished his dangerous sinker.
"I'm excited to be back here," Treinen said. "This is where it started."