When the Astros lost the services of Carlos Correa in free agency, I wasn’t necessarily pessimistic about the future of the shortstop position. I possessed reasonable confidence that Jeremy Peña would eventually become — at worst — a league-average shortstop, thanks to his already strong defense. That is a solid foundation to build upon. But with only 133 plate appearances above Single-A, the pressing question in the offseason was whether his bat would be ready for major league pitching in 2022. While he made impressive gains at the plate during his lone season in Triple-A, he was relatively untested. However, Peña, in his rookie campaign, has more than held his own with a .265/.309/.464 slash line and 119 wRC+ in 315 plate appearances.
But Peña’s performance thus far, although admirable, does leave room for improvement. There remain weaknesses to address at the plate. Of the most immediate concern, Peña’s performance against breaking pitches requires monitoring as pitchers continue to adjust. While his approach against fastballs has proven beneficial to the tune of a .395 wOBA/.417 xwOBA with only a 15.1 percent whiff rate, he has struggled more against breaking pitches, as evidenced by his .311 wOBA/.260 xwOBA and a 41.7 percent whiff rate. These struggles become even more apparent when he chases pitches outside the strike zone, as judged by his chase and miss rate by month.
It isn’t a coincidence that Peña’s production improved in May as he exhibited improved plate discipline against that subset of offerings. On a monthly basis, his .342 wOBA against breaking pitches in May outpaces his performance in April (.286), June (.304), and July (.307). It was also his best overall month as a hitter in 2022 with a 148 wRC+. By reigning in his aggressiveness at the plate, Peña demonstrated what his ceiling could look like if that kind of plate discipline became more of the norm, not the exception. Unfortunately, this improvement evaporated as quickly as it came, with a trip to the IL in the middle of June also involved.
As I mentioned, pitchers are adjusting to Peña’s at the plate as he has more exposure at the major league level. They’ve begun to concentrate more on breaking pitches, almost exclusively sliders, in the lower region of the strike zone in July compared to previous months. There was some evidence of this approach in May, but Peña’s improved discipline at the time mitigated the effects of this plan. But in light of the rookie shortstop regressing, they can now attack that region of the zone in earnest again.
This adjustment made by the opposition and his subsequent struggles has partially contributed to Peña posting a 105 wRC+ from the start of June compared to the 133 mark from April through May. Until Peña learns to lay off breaking pitches, especially sliders, thrown low in the strike zone, he will continue to see his offensive production capped. But some of this regression was expected as Peña continues to make adjustments. I am curious to see how he adjusts back and if his improved plate discipline from May returns during the season’s unofficial second half.