The Red Sox announced five transactions this morning, including the news that left-hander Zach Penrod’s contract has been selected to the big league roster. Catcher Tyler Heineman was designated for assignment to open up a spot on the 40-man roster, and left-hander Cam Booser and right-hander Zack Kelly were both optioned to Triple-A Worcester to create space on the active roster. Boston also called up southpaw Bailey Horn from Triple-A. Julian McWilliams of the Boston Globe (X link) was the first to report on the Penrod, Booser, and Horn transactions, while MassLive.com’s Chris Cotillo (via X) reported yesterday that Kelly was being optioned.
Kelly and Booser were two of six pitchers used by the Red Sox in Friday’s 5-4 loss to the Yankees, so today’s moves brings some fresh arms into Boston’s relief corps. For Penrod, he is now on the verge of his Major League debut, making quite a culmination of a six-year pro career that began as an undrafted free agent.
Penrod pitched briefly with the Rangers’ rookie league club in 2018 but he then spent two years on the sidelines due to both a Tommy John surgery and the canceled 2020 minor league season. The southpaw returned to pitch in the independent Pioneer League from 2021-23, and this performance caught the eye of Red Sox scouts and led to a minor league deal partway through the 2023 season. This year, Penrod has a 4.16 ERA over 62 2/3 combined innings at Double-A and Triple-A ball, as well as a huge 34.8% strikeout rate.
There is a pretty wide variance in those minor league numbers, as Penrod posted a 2.80 ERA in 35 1/3 Double-A innings and a much heftier 5.93 ERA in 27 1/3 frames in Worcester. Control has been a bit of a question mark for Penrod throughout his career, and his walk rate also spiked up to 16.1% in Triple-A after a more palatable 9.1% number in Double-A action.
Still, the strikeouts are playing at both levels, and Penrod’s upper-90s fastball makes him an interesting bullpen weapon for the Red Sox to explore. Penrod has mostly started throughout his pro career but worked out of the pen for 10 of his 15 appearances in Worcester, so Boston figures to use him in a long relief role here at the tail end of the 2024 season. As Alex Speier of the Boston Globe explored back in May, Penrod’s development of a slider as a third pitch after his fastball and changeup could help him carve out a path as a starter, but the 27-year-old is surely pleased to work in the majors in any capacity.
The Red Sox acquired Heineman in a trade with the Mets back in February, and he has spent almost the entire season in the minors save for two games at the MLB level. Connor Wong and Reese McGuire handled most of the catching duties for the Sox this season, and after Danny Jansen was acquired at the trade deadline, McGuire was outrighed to Triple-A and Heinemen was pushed even further down the depth chart.
With his two appearances in a Red Sox uniform, Heineman has now now suited up for five different teams at the big league level over his five seasons in the Show, and he has also been organizational depth for six other franchises. Heineman has hit .216/.297/.280 over 286 career plate appearances, with 174 of those PA coming as a member of the Pirates and Blue Jays in 2022. Because Heineman has been outrighted before, he has the ability to elect free agency and reject an outright assignment from Boston if he clears DFA waivers.