Self-discovery has since led him to find his fastball.
"When your job depends on it, you're going to try to be the best pitcher you want to be," Neshek said from the Cardinals' spring clubhouse, where he has been for a month now as a non-roster invitee fighting for a bullpen job. "I needed to get my fastball back."
Neshek has been showcasing that fastball this spring, much to the delight and surprise of the Cardinals, who knew that he had become slider dependent in recent years. The club's radar gun has registered a fastball as high as 92 mph for Neshek, who said he doesn't think he's shown that sort of velocity since his early years (2006-08) with the Twins.
It has all produced an early spring résumé -- five innings, six hits, two earned runs, one walk, seven strikeouts -- that has Neshek in strong position to turn a Minor League contract into a Major League opportunity as a member of the Cardinals' bullpen.
"It looks good to me," manager Mike Matheny said of the right-on-right specialist. "The ball is jumping out of his hand. You can tell it's an uncomfortable at-bat. The lefties look just as uncomfortable as the righties do. I know those numbers have always been skewed the other way. He's got plenty of life on the ball, no question."
Nowadays, Neshek kids about how the A's will probably forever label him the "slider guy," because of how reliant he became on that pitch during his two-year stint in Oakland. That's a label he vowed to dissolve in 2014.
In four seasons with the Twins and another one in San Diego, Neshek had never thrown sliders more than 50 percent of the time. With Oakland, more than three-fourths of the pitches he threw were sliders. That cost him the element of surprise, something his father also pointed out to him during a candid offseason conversation. It was all enough urging for Neshek to commit to throwing the pitch more often this spring.
Even he has so far been surprised with the results.
"After my second outing, I felt just awesome," Neshek said. "And then I looked up [at the scoreboard radar gun] and said, 'Wow, I hit 90 [mph].' Last year, I would hit 90 a few times, but it was a struggle to hit that. I feel like now it's at ease."
Neshek is also throwing the pitch out of the windup now, too, in order to add deception. Neshek pitched almost entirely out of the stretch with the A's, he said, because he never felt comfortable otherwise.
Relegated to pitching mostly in low-leverage situations with the A's, Neshek said he also lost that incentive to try and get any of it back -- his fastball or the fluidity he needed to pitch out of the windup with his sidearm delivery. That has changed now that his job depends on it.
"I think the A's got sick of me, because I kept throwing more and more sliders," Neshek said. "You can't keep doing that. I pitched in situations that didn't matter, and it was really hard to get pumped up. So I just kept doing it."
The bad habit, Neshek believes, actually developed with dominant intentions. Traded from Baltimore to Oakland in August 2013, Neshek struck out three of the four batters (on sliders) in his first appearance. Catcher Derek Norris was so impressed that he called all sliders the next day, too.
"He figured they couldn't hit it -- which was right, but you couldn't fool them," Neshek said.
Nevertheless, the results were too good to tinker with the strategy. In his first 18 appearances with the A's, Neshek held opponents to a .143 batting average and one run. According to brooksbaseball.net, 93 percent of the pitches Neshek made to right-handed batters were sliders. A year later, that percentage was 83.
There was no longer the potential surprise.
"I wasn't getting the whiffs," Neshek said. "I would get them to two strikes, but then I couldn't put them away."
Neshek's 6.5 strikeouts-per-innings pitched in 2013 was the lowest of his career. He wants to get that ratio up to one per inning again, something he has done so far this spring. Now there is the task of committing to that fastball the way he once did.
"When I was at my best in 2006-07, that was my bread and butter," Neshek said of his fastball. "When you get that speed, with my deception, it comes in there good. It's just an extra element. You'll get more foul balls, and then you can use your other stuff. That's huge, I think."