Phillies’ Corey Knebel has a ‘surprise’ pitch four years in the making. But he won’t tell you what it is.

CLEARWATER, Fla. — Corey Knebel is not new at this. Over his seven-year career, he’s pitched in 266 big-league games, and closed in nearly half of those outings (108, to be exact), to the tune of a 3.23 ERA.

The Phillies signed Knebel to a one-year, $10 million deal just hours before the lockout started, preventing him from working extensively with the Phillies’ pitching and training staffs over the winter, but he said it mostly felt like a normal offseason. He ramped up the same way he always does, in Austin, Texas, and was able to face some big-league and minor-league hitters in the area.

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At this point, Knebel, who will be the Phillies’ closer, has his routine down. But there were a few notable differences he made this offseason, which could make a significant impact on the Phillies this season. Knebel primarily relies on his four-seam fastball and his curveball, but since 2018 he has been toying around with a third pitch, which as of now, he’s referring to as a “surprise.”

“I can’t share what it is right now,” he said with a grin, “but you’ll probably see it in the spring. I want to keep it a surprise.

“It’s turned out to be pretty good, though. The numbers were … I wouldn’t say par, but maybe slightly above par. Something to keep working on this spring, and maybe bust it out in a couple of games.”

Four years might sound like a long time to be working on a single pitch, but as Knebel noted, relievers have less opportunity to test out what works and what doesn’t because they have shorter outings. While starters have ample innings to experiment, a closer might have one or two innings, at most.

But Knebel thinks he’s finally at the point where he’s able to throw his “surprise” pitch in games, and depending on how that goes, perhaps even fold it into his regular repertoire.

Without knowing what the pitch is, it’s hard to analyze the impact it would have on his other offerings. But Knebel’s current two pitches have two distinct shapes, and thus are easier for hitters to anticipate. His curveball breaks quite a bit, and comes out of his hand at a different angle than his four-seam fastball. If he does end up adding a third mystery pitch — perhaps a variation of a cutter/slider or a changeup/splitter — it could add an element of deception.

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A slider or a changeup would have less downward movement than his curveball would, so it would be easier for Knebel to disguise those pitches at his release point, making it trickier for the hitter to see what’s coming. To an opposing hitter, a slider or a changeup might look more like a four-seam fastball coming out of his hand.

It will be something to keep an eye on as spring training games start this week (the Phillies’ first game is on Friday against the Tigers in Lakeland, Fla.). When Knebel faced live hitters Thursday, no “surprise” pitches were thrown. But if it all works out, his “surprise” pitch could make Knebel, who is coming off a strong 2021 season with the Dodgers (2.45 ERA in 25⅔ innings), even stronger with the Phillies in 2022.

Knebel was one of the most dominant relievers in baseball in 2017 with Milwaukee, when he compiled a 1.78 ERA through 76 innings with 39 saves and 126 strikeouts. That performance earned him a trip to the All-Star Game. But he wasn’t able to replicate it in 2018, and underwent Tommy John surgery just before the beginning of the 2019 season, after experiencing some discomfort in his ulnar collateral ligament in his right elbow in spring training.

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He struggled in 2020, his first full season back after the procedure, but returned to form in 2021 with the Dodgers.

This offseason marked the first winter Knebel spent working with a physical therapist. The trainer, Kody Krupps of ROI physical therapy and sports performance, led Knebel through a series of shoulder and mobility exercises in an attempt to prevent any injuries in 2022.

“This is stuff that I do during the season,” Knebel said, “but I was able to do it in the offseason, which is even more beneficial.”

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The results are promising, so far. Knebel says he feels “good,” and manager Joe Girardi, after watching Knebel face live hitters on Thursday, was impressed with his closer’s stuff.

“He looked really good,” Girardi said. “His fastball had life, his curveball had great depth. That was good to see. That’s the guy I remember.”