In 2020, the Pirates might be able to hit enough to stay in contention over the looming 60-game sprint of a season.

However, their pitchers may get hit around the yard on a nightly basis just as hard.

Or worse.

One X factor in how the starting rotation performs is the potential improvement of Mitch Keller. The highly regarded prospect posted ugly numbers in his first partial season at the big league level.

The right-hander ended 2019 with a 1-5 record, a 7.13 ERA, and a 1.83 WHIP. His weighted on-base average (wOBA) of .392 was in the bottom 2% of the league, according to Baseball Savant.

Despite those statistics, new manager Derek Shelton came to Pittsburgh excited to see what Keller could do in his second go-round at the big league level.

“When I got the job a lot of pitching guys in the game I respect — at multiple levels — said, ‘You are going to love this guy’s stuff,’” Shelton said on Monday. “We are talking about a 23-year-old kid with a bright future.”

Encouragingly, the issues Keller had last year weren’t so overwhelming that he went into the offseason with his head swimming over how to improve. He identified two clear-cut tasks to improve his chances of getting big league hitters out in 2020.

1. Make his fastball harder to hit.

2. Develop a changeup.

Obviously, improving the fastball will aid the changeup by extension. But Keller feels both are necessary to make him more competitive on the mound.

Crafting the changeup is a big picture endeavor. He essentially needs to invent the pitch for himself. He barely threw one last year. And when he did, it got smacked by opposing hitters.

Again via Baseball Savant, Keller only threw 28 changeups last year (just two against right-handed hitters), accounting for a scant 3.7% of his pitches. Batters had a collective slugging percentage of 1.000 against it.

So maybe it’s a good thing that he didn’t throw it more often.

Now, though, that pitch may become necessary.

“The changeup is a development pitch for any young starter,” Shelton said. “Usually guys have either a breaking ball or a changeup when they come in, and they develop the other.”

First thing’s first on that pitch. Keller needs to hone a grip for it. And, by his own admission, it’s still a work in progress.

“It’s not a standard grip,” Keller said. “I’m still messing around with it. It’s not a set-in-stone grip. I’m just trying to tinker. Figure things out that I like and what feels good.”

To Shelton’s point, though, at least Keller’s breaking pitches were effective enough last season to offset the lack of a changeup. Keller’s slider resulted in just a .200 batting average against and a 47% whiff rate. His curve yielded a batting average against of just .130.

So that part of his arsenal provides a positive platform.

The bigger issue was Keller’s fastball, which opposing hitters thumped. Keller used his four-seam fastball 59.5% of the time in 2019. And the rest of the league knocked it around various parks to the tune of a .461 batting average, a .719 slugging percentage, and a .505 wOBA.

That’s despite a pretty decent average velocity of 95.4 miles per hour and a spin efficiency in the lower 90s in terms of percentile.

But, for whatever reason, the velocity and spin Keller was creating wasn’t manifesting in enough movement of his fastball.

So, via his work with the Rapsodo pitching data, Keller worked on increasing his spin rate even more so as to ratchet up some movement.

“Using that feedback and just tinkering,” Keller said. “Just a thought in your mind to get some more backspin. For every guy it’s different. But, for me, it was just a thought in my head of what I wanted the (spin rate) numbers to do. Whatever that might feel like — on the mound, the release — just trying to match that up with the numbers I (wanted). I made mental notes. Wrote some stuff down, and thought about what got me to that point.”

On the surface, it sounds like Keller has some theories outlined. Now it’s just a matter translating onto the field.

Big picture, though, that’s a major league pitcher admitting two of his four pitches need a lot of work.

But given the gigantic experiment that 2020 is to begin with, I can’t think of a better circumstance for Keller to work through those growing pains on the fly at the major league level.

Because if Mitch Keller becomes what Mitch Keller was supposed to be, then suddenly that Pirates rotation starts to look a lot more prepared to keep up with its anticipated offensive support.

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