PEORIA, Ariz. -- After three days of workouts, every healthy Padres pitcher has now thrown a formal Spring Training bullpen session.
If you watched the club last year, you've already seen these guys pitch. But in some cases, they won't be the same pitchers in 2019.
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Several San Diego hurlers are making tweaks and adjustments to their arsenal of pitches -- generally in response to their successes and failures last season. With that in mind, here's a breakdown of the prominent new pitches on the Padres' staff this spring.
Joey Lucchesi
He's working on: A cutter. Lucchesi was a two-pitch pitcher for most of last season. He sported a two-seam fastball and a swing-and-miss offspeed pitch, which he calls a "churve." Now, Lucchesi has added a cutter, which is mostly just a four-seam fastball with natural cut. Velocity-wise, it's similar to that of his two-seamer, but it moves in the opposite direction.

Why it might help: As deceptive as Lucchesi's churve was last season, he almost certainly needs another pitch if he's going to be a successful starter who can work deep into games. Lucchesi thinks his cutter might be especially effective against right-handed hitters, who hit him to the tune of an .800 OPS last season.
"I'm really excited about it," Lucchesi said. "I feel like I've just got something else in my pocket as a secret weapon."
Eric Lauer
He's working on: A distinct slider. For most of last season, there was a blurred line between Lauer's cutter and his slider (which began as one pitch). Lauer began adding more depth to his slider toward the end of last season, differentiating it from his cut-fastball.
Why it might help: It's a putaway pitch. Lauer got whiffs on 26 percent of his sliders last season -- his most of any pitch. When he used it to end at-bats, those at-bats resulted in strikeouts 36 percent of the time.
"He found a feel for how he can shape them a little bit differently, so [the cutter] stays a little bit on-plane to be able to throw for a strike and get weak contact," said catcher Austin Hedges. "The [slider] is a little bit bigger and he can throw it back-foot or down-and-away to a lefty to get the punchout.
Bryan Mitchell
He's working on: A different curveball. "Maybe even call it a slurve," Mitchell says. It's going to be tighter, and the goal is to give Mitchell a putaway pitch that can be mistaken for his fastball.
Why it might help: Mitchell's overall chase rate dipped to a career-low 20.7 percent. That's almost certainly the result of a curveball that was too easy to pick up. If Mitchell's going to win a rotation spot, he needs a bona fide putaway pitch, and he's hopeful his "slurve" can do the trick.
"It was just breaking too soon last year," Mitchell said. "Hitters could pretty much eliminate it last year, because I wasn't throwing it for strikes. I'm trying to blend it more with the fastball, make it more deceptive."
Robert Stock
He's working on: A cutter. Stock already boasts a high-octane fastball paired with a biting slider. Now he's looking to add a cutter that sits around 90 mph.
Why it might help: Despite velocity in the upper 90s, lefties batted .353 against Stock's fastball last season -- more than 100 points better than right-handed hitters. If Stock's cutter is effective, it could neutralize that effect.
"It could be good to lefties to get inside on them," Stock said. "Lefties hit me pretty good last season. That's why I'm in Spring Training -- to throw it a bunch and find out."
Kirby Yates
He's working on: Bringing back his slider. Yates' fastball/splitter combo was devastating last season. He's used those two pitches to become the current owner of the highest strikeout rate in Padres history. In the meantime, Yates' slider usage dipped from 32 percent in 2016 to 5 percent last year.
Why it might help: It might not. Yates could very well scrap the plan to use a slider by the end of spring. But he's tinkering with the pitch and trying hard to make it work. There's a simple explanation for why:
"It'll never overtake the split," Yates said. "But it's nice to have another trick in the bag. I'm back in the division again for the third year. There are some guys who have seen me a lot, and it'd be nice to have another wrinkle."
Jacob Nix
He's working on: A high-velocity curveball. After watching video, Nix noticed he'd fallen into a pattern of opening his upper body as he rared back. That caused both the spin and the velocity on his curveball to drop. The goal is to get back to the pitch that he used as a putaway offering in 2017 at Class A Advanced Lake Elsinore.
Why it might help: Simply put, Nix needs this pitch. He had some minor success with weak contact last season. But he mostly struggled to finish at-bats, striking out only half a hitter per inning.
"I'd never thrown a curveball under like 78 mph until after Elsinore," Nix said. "Then I started to see that velo fall off. I don't know if it's because I started to throw the [heck] out of it, trying to make it do too much. But it happened. It wasn't my swing-and-miss pitch. It wasn't a pitch where I'm throwing this, and there's no way you're touching this. If I can get back to that, it'll be big."