The Astros need rotation depth and Tanner Roark could fit the bill

The Astros are most likely losing Gerrit Cole in free agency. Zack Wheeler is presumably outside of the club’s price range. Signing Stephen Strasburg, at best, is a pipe dream. Unless club ownership is willing to expand the budget in a notable way, Houston is simply not in play for any of the top pitchers, much less any highly sought after free agent, out on the open market.

That said, the Astros are already in an enviable position when it comes to talent already under contract. Another run at the AL West title is still in play for 2020, although there isn’t a conceivable route to fully replace Cole’s contributions to the pitching staff over the last two seasons without largely eclipsing the collective bargaining threshold of $208 million. There is no way to gloss over the impact of Cole’s departure to a staff that was one of baseball’s best in the past two seasons. Instead, the Astros will likely need to find ways to improve roster without busting their own imposed budget constraints. The signings of Charlie Morton and Wade Miley to short term, low risk contracts stand out in recent memory.

For the Astros, quality depth is the theme of the offseason when it comes to the rotation. Justin Verlander and Zack Greinke are expected to lead the starting staff next season, with the hopeful reemergence of Lance McCullers Jr. and the potential development of Jose Urquidy also in play. But there are plenty of question marks with this approach, especially with Cole and Miley’s likely departures accounted for in their plans. The Astros, for better or worse, will have to find a way to replace those two and their combined sixty-seven starts from 2019. That’s a lot of innings and Houston will likely need at least one, or even two, veteran starters to help fill the void.

Well, there are a few starters who could wet the Astros’ whistle this offseason. As Brian McTaggart of MLB.com pointed out here, we should pay close attention to recently non-tendered pitchers Taijuan Walker, Jimmy Nelson, and Kevin Gausman. There is also former Astro Jordan Lyles, who made twenty-eight starts in 2019, to watch. Julio Teheran is another, especially if a club feels like they can at least negate his declining four-seam velocity. And there is Tanner Roark, who split the recent season with the Reds and A’s, as a starter to consider as a possible buy-low candidate.

In short, Roark’s profile ought to pique some interest from teams. Sure, his 4.35 ERA and 4.67 FIP in 165 ¹⁄₃ major league innings last season doesn’t inspire much confidence along with a strikeout rate that only ranks in the 41st percentile. However, the right-hander is durable as he has five campaigns of at least thirty starts in his last six seasons to his credit. Although it doesn’t seem as emphasized as much in recent years, there is still value in pitcher durability. Only fifty-two pitchers made at least thirty starts last season, for example. There are varying results in the mix, yes, but a pitcher generally doesn’t make at least thirty starts in a single season if they are an outright scrub.

Outside of his durability, though, Roark does have an additional point interest, such as his curveball’s spin rate. As we already know, the Astros have demonstrated a strong tendency in the past about targeting pitchers with underrated spin rates, including curveballs. Of all notable starters still available, Roark ranked fifth in curveball average spin rate at 2746 RPM in 2019. The other four in front of the right-hander? Cole, Rick Porcello, Strasburg, and Teheran. Roark actually finished the season in the 82nd percentile in average curveball spin rate, which is remarkably higher than Miley’s 42nd percentile rank. His curveball, in particular, demonstrates some noticeable drop. On the average, Roark’s curveball dropped sixty-five inches, which is larger than the league average drop of fifty-four inches.

Higher spin rates and large pitch drops won’t always translate into optimal results, however, as Roark’s curveball last season posted a .310 wOBA and .299 xwOBA. For context, the league average wOBA and xwOBA for a curveball was .278 and .269 for all pitchers in 2019, respectively. On the other hand, his curveball generally saw better results before last season for multiple years in a row.

It is worth the consideration whether further usage alterations are in order for Roark, who has seen his sinker rate drop from sixty-four percent in 2015 to just thirty percent last season. Could he benefit from dropping the sinker all together and focus more on his four-seam fastball? Both his four-seam and sinker each have similar velocities, only separated by less than one mile per hour on the average. In today’s emphasis on launch angles, sinkers aren’t necessarily a popular pitch of choice. The major question I have about this idea is whether Roark can throw his four-seam with a higher velocity on a consistent basis. Morton, who is an obvious comp in this regard, had an average four-seam velocity of 91.6 miles per hour in 2016, the season before he signed with Houston. Since then, the former Astro has averaged 95.4 miles per hour on his four-seam as he deemphasized his two-seam fastball. Roark isn’t Morton, however, as the results could vary wildly. But again, it is worth consideration.

Yes, Roark isn’t one of the sexiest names on the free agent market, but he is someone who could help stabilize the back end of the Astros’ rotation next season. He only made $10 million last season and could earn a contract worth at least $7 million annually this winter, which could be quite reasonable. But that possible price may just push him past Houston’s reach if the collective bargaining tax is a real concern, although I could be wrong here. Regardless, is there a lot of untapped potential there in Roark? Probably not. At the same time, Houston needs a bit of veteran durability even if the results are just average to slightly above. There is value in the known along with possibility that the unknown could be even better.