Tahnaj Thomas is the best relief prospect the Pirates have to offer. He fully transitioned to the bullpen this year and worked to the tune of a 3.02 ERA, 3.63 FIP, and 1.26 WHIP. His peripheral numbers were also decent, with a 24.4% strikeout rate, 9.4% walk rate, and 0.71 HR/9. Thomas was fully entrenched in the role by the time summer rolled around. From June through the end of the season, Thomas owned a 2.10 ERA, 2.83 FIP, and 1.03 WHIP. He had a strong 27.7% K-rate, along with a 7.3% walk rate. Thomas surrendered just two home runs in his final 34.1 innings of work.
Thomas has always thrown hard, averaging out in the upper-90s. He also throws a plus slider, but the question has always been if he could ever develop the third pitch he needed to become a starter. But in a relief role, his fastball/slider combo is much more effective. With a much better walk rate, he looks to make a name for himself in 2023.
One last relief prospect worth diving into is Colin Selby. Selby was the owner of a 2.20 ERA, 2.59 FIP, and 1.26 WHIP at Altoona. He may have had a mediocre 10.1% walk rate, but he struck out nearly 30% of the batters he faced with a 29.7% strikeout rate. His 53.8% ground ball rate helped him allow just one home run across 32.2 innings. Selby throws a nice curveball and was hitting the upper-90s at the Arizona Fall League. Selby has become quite the underrated relief prospect who could force himself into the Pittsburgh Pirates future plans.
Other than Selby and Thomas, the Pirates have Hunter Stratton, Joe Jacques, Travis MacGregor, Noe Toribio, Osvaldo Bido, Ricky DeVito, Cameron Junker, Jeffrey Passantino, Enmanuel Mejia, Will Kobos, Cristian Charle, Eddy Yean, Wilkin Ramos, Michell Miliano, Dante Mendoza, and Jake Sweeney. There’s definitely a chance the Pirates lose someone like Yean, Mejia, or DeVito. They might not be high-end prospects, but they have a prototypical Rule 5 Draft pitcher skillset. All three are high-risk/high-reward with good velocity or breaking offerings but have lacked consistent command, which has been the main point of their struggles.