Justin Martinez

Martinez struggled in his first exposure to the big leagues in 2023 and failed to break camp with the Diamondbacks last spring. The 23-year-old missed plenty of bats in the minors, striking out 14 across 6.2 innings for Triple-A Reno last year before his recall in late-April. Martinez still had trouble throwing strikes in the majors, but worked around his 11.7 percent walk rate to produce a solid 2.48 ERA over 72.2 innings. The flamethrower walked 36 to inflate his WHIP (1.31), but his splitter was absolutely devastating (.098 BAA, .122 SLG), generating a 54 percent whiff rate that was 3rd-highest in the league for that pitch type. He also averaged 100.3 mph on his sinker while inducing ground balls at a 60 percent clip. Martinez's ascension to the back-end of Arizona's bullpen was no surprise and he racked up eight of the team's 13 saves after Aug 1. He enters 2025 as the presumed favorite for saves in Arizona, but closing is no guarantee due to the traffic he allows.