Tampa Bay Rays: Robert Stephenson another underrated pickup?

The Tampa Bay Rays acquired right-handed reliever Robert Stephenson from the Pittsburgh Pirates for shortstop Alika Williams, the team’s first-round pick in 2020. Stephenson had struggled in his limited time with Pittsburgh, with a 5.14 ERA in 14.0 innings. Meanwhile, Williams had bashed 11 doubles with a .731 OPS in Double-A. Williams was a contact-oriented shortstop with a strong glove, but has struck out 173 times in his three minor league seasons.

Stephenson has intriguing traits under the hood, hence the Tampa Bay Rays acquiring him. A good rule of thumb, if the Rays are asking about a pitcher, you better figure out what they see before it is too late. Stephenson was a former first-round pick by the Reds in 2011, and still throws hard, averaging 96.9 mph on his fastball, per Baseball Savant. Despite the velocity, Stephenson throws nearly 63 percent sliders. The slider is borderline elite, registering a Stuff+ rating of 138, where 100 is league average. Of all Pittsburgh pitchers, Stephenson posted the highest overall Stuff+ at 129. So was command the issue? Not really, as Stephenson’s 98 Location+ rating is basically league average.

Well, Stephenson’s fastball, which has slightly above-average vertical movement, has leaked towards the middle of the zone far too much this season. While the slider has consistently finished low and to Stephenson’s gloveside, his fastball has been down in the zone far too much considering his movement profile. In a recent interview with Tread Athletics, Pete Fairbanks mentioned how the Rays emphasize throwing the ball down the middle. Could this be the solution to unlocking Stephenson’s lethal arsenal? For Fairbanks, it was at least part of his transformation to dominant reliever. Another Tampa Bay addition, Jake Diekman, has cut his walk rate by over nine percent since joining the team.

In terms of Stuff+, Stephenson slots into second place behind Diekman on Tampa Bay’s staff, with Diekman checking in at 131. Overall, Tampa Bay has 17 pitchers with a Stuff+ rating of 100 or higher. The Rays’ player development department has a stellar reputation, and Stephenson seems like their ideal candidate.

Williams will join a crowded farm system in Pittsburgh, but will likely take over the starting shortstop position at Triple-A Indianapolis. With Oneil Cruz likely out until at least August, there may be an opportunity for Williams to debut in Pittsburgh. FanGraphs is bearish on his future, likening his future to more of a defensive-replacement than a true everyday shortstop.