The Diamondbacks entered Spring Training with four rotation spots in place. Zac Gallen and Merrill Kelly are the top two on the staff. Madison Bumgarner will get another crack in the middle, while Arizona brought back Zach Davies on a one-year free agent deal to take a back-end spot.
Who would secure the fifth spot was one of the more interesting decisions for the Snakes in camp. As MLBTR’s Darragh McDonald explored in early January, that battle looked likely to come down to four hurlers: Ryne Nelson, Drey Jameson, Tommy Henry and Brandon Pfaadt. Jameson and Nelson, both of whom made their big league debuts late in the 2022 season, seemed the early favorites.
That indeed now appears to be a two-person race. Arizona reassigned Pfaadt, who is not yet on the 40-man roster, to minor league camp over the weekend. They optioned Henry to Triple-A Reno this afternoon, taking him out of consideration for an Opening Day job as well.
Neither Jameson nor Nelson has done much to seize the job this spring. The former has allowed eight runs in 9 2/3 innings, while the latter has been tagged for nine runs in the same amount of work. Jameson has at least managed a solid 12:3 strikeout-to-walk ratio, while Nelson’s 10:6 mark is less impressive.
Both pitchers fared well in very limited MLB looks last year. Jameson made four starts and posted a microscopic 1.48 ERA through 24 1/3 innings. That came with an excellent 56.1% grounder percentage and above-average strikeout and walk numbers. It was a very strong debut effort but won’t completely erase concerns about the ghastly 6.95 ERA he’d posted over the 114 Triple-A innings he’d thrown prior to his promotion. Reno is among the hardest places in affiliated ball to pitch, which certainly didn’t do him any favors. That said, some prospect evaluators have suggested the Ball State product is likelier to settle into a bullpen role than a rotation because of concerns about his command.
Nelson has had some relief concerns himself, though he’s generally credited for more advanced command than Jameson. He doesn’t throw quite as hard and didn’t miss as many bats in his brief big league look as Jameson did. Nelson had similarly strong bottom line numbers in a cup of coffee, however, allowing four runs in 18 1/3 big league frames. Over 136 innings in Reno, he’d posted a 5.43 ERA with roughly average strikeout and walk numbers.
Henry had the most MLB work of this group in 2022, starting nine games. He didn’t find the early success of Jameson or Nelson, pitching to a 5.36 ERA with below-average strikeout and walk rates in 47 innings. Henry allowed 11 runs in 16 1/3 frames in camp before being optioned. Pfaadt is arguably held in the highest regard of the bunch but is the only one who hasn’t made his big league debut. The 24-year-old made 19 starts at Double-A Amarillo and 10 with Reno last season, combining for a 3.83 ERA in 167 innings. He allowed five runs with 15 strikeouts and four walks in 12 innings this spring.