Austin Pruitt Is the Astros’ Latest Pitching Project

The Astros received some bad news about Justin Verlander’s health yesterday after he left his spring start early on March 8. The results of his MRI showed a lat strain and he’s been shut down without a timetable to begin a throwing program. His availability for opening day is definitely in jeopardy and it wouldn’t surprise me to see him miss at least the first month of the season as he ramps up his workload during extended spring training.

Losing Verlander for any amount of time is concerning for the Astros because their depth behind him is rather lacking, as Jay Jaffe explained yesterday. The loss of Gerrit Cole, Wade Miley, and Collin McHugh has left the back end of the Astros rotation rather open. And with Verlander out for the foreseeable future, that opens up another spot temporarily. Zack Greinke, Lance McCullers Jr., and Jose Urquidy should hold down the first three places, leaving two to a group filled with question marks. Josh James, who was likely leading the competition for the fifth spot, likely earned a role in the rotation with Verlander’s injury. That means the battle for the final spot comes down to Austin Pruitt or Framber Valdez, with Forrest Whitley an extreme long shot.

Both Pruitt and Valdez have collected less than 200 innings at the major league level, though Pruitt is already 30 years old while Valdez is just 26. Neither has been all that impressive during their short big-league careers. Valdez has the raw stuff, including a plus curveball and a mid-90s fastball, but he simply can’t control it. Pruitt doesn’t have the same raw stuff, but his repertoire has elements that are intriguing. There may be enough there that the Astros can tinker with to help him reach his ceiling.

We can pretty easily identify a hypothetical model pitcher the Astros have tried to acquire and develop over the last few years. We would start with extremely high spin rates on both their fastball and their breaking balls. If they were acquired from another organization, they probably weren’t using their breaking ball as often as you’d assume based on its quality.

Pruitt fits pretty closely to that model. He joined the organization in a small trade with the Rays this offseason. He had spent most of the past three seasons shuttling between the majors and Triple-A, making 67 appearances for Tampa Bay, 10 of them starts. But that raw number of starts is a little misleading. During the past two seasons, he’s been used pretty extensively as a bulk reliever after an opener started a game. In all, he’s compiled a 4.17 FIP that sits well below his 4.87 ERA.

But what about his pitch arsenal? As you might have expected, it begins with a pair of high-spin breaking balls. His curveball averages nearly 3000 rpm, which sits in the 98th percentile among pitchers who threw at least 100 pitches in 2019. His slider averages over 2600 rpm, sitting in the 87th percentile. And he was able to improve the shape of both pitches in 2019 while maintaining the velocity and spin rate on each of them.

Last year, he added both horizontal and vertical movement to his slider. It’s now dropping 1.4 inches and breaking 1.1 inches more than sliders thrown at similar velocities, a huge improvement over its below-average movement profile in years past. Changing the shape of his slider resulted in a career-high whiff rate with the pitch. He also added a little horizontal movement to his curveball while recovering its vertical movement to where it was in 2017. His curveball also saw a career-high whiff rate in 2019.

Here’s what these two pitches look like in action:

Slider

Curveball

When he’s locating these breaking balls down below the zone against both right- and left-handed batters, he’s been extremely effective. But his curveball has been hit pretty hard if it’s located up, even if it’s at the bottom of the strike zone. On curveballs located in the zone, opposing batters collected a .573 wOBA, nearly 250 points above the league average. To maximize the effectiveness of this pitch, he needs to locate it down and out of the zone. If he needs to locate a breaking ball in the zone, his slider is more than capable of generating whiffs and weak contact if it’s left in the zone.

He threw these two pitches a little more than a third of the time last year. His other secondary offering is a good changeup that’s used to keep left-handed batters at bay. With two excellent breaking balls and a good changeup, you wouldn’t expect to see a significant platoon split. But Pruitt has surprisingly struggled against right-handed batters. They torched him last season to the tune of a .380 wOBA, and that heavy reverse platoon split has been true throughout his career.

The culprit is likely the final pitch in his repertoire, his fastball. He throws it around 40% of the time and it averages 92 mph, a little below average for a four-seamer in the modern era. The pitch does possess a high spin rate but the shape of the pitch is a little odd. It’s arrow straight with very little horizontal movement and it doesn’t have as much ride as you’d expect from a high-spin-rate fastball. His heater’s vertical movement sits in the 31st percentile among all four-seamers thrown at least 100 times last year. That means all the spin he’s imparting on the pitch isn’t contributing to the pitch’s movement, a concept known as active or true spin.

For a four-seam fastball, the active spin rate is affected by both the velocity and spin axis of the pitch (something you’ve probably picked up on if you’ve been following Michael Augustine’s work on FanGraphs). Pruitt’s fastball spin axis is nearly horizontal (185 degrees), which means a lot of the spin he’s imparting on his heater is wasted. Baseball Savant confirms this: Pruitt’s fastball is listed with 66.8% active spin, 639th out of 690.

Even though Pruitt’s fastball doesn’t have as much ride as we’d assume based on its spin rate, he still locates it at the top of the strike zone pretty often. That’s helped him post a league-average whiff rate with the pitch but it’s more often come at the cost of some extremely loud contact. Due to the shape and characteristics of the pitch, it generates more contact on the ground than a typical four-seam fastball. The challenge for Pruitt is to find a balance between using his fastball up in the zone to generate whiffs while being able to locate it down to avoid getting hit hard.

Adjusting his pitch mix to include more of his breaking balls at the expense of his fastball is another seemingly simple change that should allow him to even out his extreme platoon splits. If he’s able to tinker with his fastball grip to shape the pitch’s spin axis, that would likely lead to a more effective heater as well. Astros pitching coach Brent Strom is no stranger to taking a pitcher’s raw stuff and maximizing it to great effect. He has his work cut out for him with Pruitt, but all the elements are there for a Collin McHugh-type turn around.