MLB Arms Part 2
Chase De Jong is slated to return as the long-relief man. De Jong was a nice surprise, pitching to a 2.64 ERA, 1.14 WHIP, and 4.74 FIP in 71.2 innings for the Pittsburgh Pirates. But there were plenty of red flags. De Jong had a 10.2% walk rate and allowed home runs at a 1.26-per-9 pace. His opponent exit velocity of 88.4 MPH was about league average, and he was greatly helped by a .222 batting average on balls in play.
But one should be skeptical of the right-hander. He had a 4.96 xFIP, 4.38 SIERA, and 111 DRA-. The issues started to present themselves at the tail-end of 2022, as he had a 4.96 ERA, 6.91 FIP, and 1.78 WHIP in September. His BAbip was much closer to the league average at .313, so where De Jong goes from here is up in the air. He’ll likely be entrusted with a low-leverage multi-inning role at the start of next season, but with multiple top prospects and his late-season struggles, the luck could be running thin for De Jong.
As things currently stand, Duane Underwood Jr. likely has a spot in the Pittsburgh Pirates bullpen. Underwood got off to a good start to the 2022 season. He pitched to a 3.96 ERA and 1.36, but a fantastic 2.27 FIP, 27.3% strikeout rate, and allowed zero home runs through the all-star break. Underwood induced ground balls 50% of the time while limiting opposing hitters to an 85.6 MPH exit velocity. Along with an uptick in pitch velocity, things were trending upward for Underwood Jr.
However, the second half was not nearly as kind to the right-hander. In his last 32.1 innings, Underwood owned a 4.73 ERA and 1.52 WHIP. While his FIP was 3.42, he also had a 4.39 xFIP, which was much closer to his actual ERA. Underwood saw his strikeout rate plummet to just 18.1%, and while he didn’t give up a home run, he let opponents bat for an 89.2 MPH exit velo against him. The velocity he gained at the start of the year also slowly faded away.
Next is Robert Stephenson. The Pittsburgh Pirates claimed the hard-throwing right-hander off waivers from the Colorado Rockies late into the year. Stephenson only pitched 13.1 innings in Pittsburgh before the season’s end, but he did solid, striking out 18, only allowing one free pass and two home runs. He did surrender five total earned runs, but it still resulted in an ERA below 4.00.
Stephenson heavily struggled with Colorado, and while that can’t be ignored, Stephenson started to pitch to his strengths for the Pirates. Stephenson’s terrific slider held batters to a .170 average and .264 wOBA. Despite its effectiveness, he used it less frequently than his four-seam fastball, which opponents hit for a .459 wOBA. However, Stephenson dropped his fastball usage rate to just 28.2%, used his slider 69.4% of the time, and even threw a curveball 2.4% after moving to Pittsburgh. Last season, Stephenson used his curveball 20.9% of the time and held opponents to a .223 wOBA. You might see very few slider/curveball relievers, but Stephenson could be one.
One last major league bullpen arm to highlight is Yohan Ramirez. Ramirez was a solid second-half pick-up acquired by the Pittsburgh Pirates from the Cleveland Guardians. He worked to a 3.67 ERA, 3.82 FIP, and 1.30 WHIP for the Bucs. He had a poor 18.1% strikeout rate and 11.2% walk rate but got batters to hit a ground ball nearly 60% of the time. With an 87.1 MPH exit velo, he allowed only one home run in black-and-gold.
But it’s reasonable to be weary of Ramirez. Despite the solid results, he also had a subpar 4.09 SIERA and 4.19 FIP. His biggest strength is preventing the home run, as he doesn’t strike out many, nor is he a command expert. But overall, he could be a solid middle-relief arm for the Pirates in 2023.