The Arizona Diamondbacks have made several roster changes, including designating left-handed pitcher Joe Mantiply for assignment, as part of a broader shakeup taking place in 2025. These moves were announced recently as the team added right-hander Jeff Brigham to the roster and signed infielder Ildemaro Vargas, while optioning infielder Jordan Lawlar and right-hand pitcher Kevin Ginkel to Triple-A Reno to create room for the newcomers.
Joe Mantiply’s Recent Performance Decline Leads to Roster Removal
Joe Mantiply, 34, has faced significant difficulties in the 2025 season after delivering solid performances in past years. Between 2021 and 2024, Mantiply pitched over 198 innings for the Diamondbacks and maintained a respectable 3.63 earned run average (ERA). During that stretch, he recorded a 22% strikeout rate, issued walks to just 6% of batters, and induced ground balls on 51.9% of balls in play, compiling three saves and 50 holds for the team.
However, this season has been markedly different. Mantiply has allowed 13 earned runs over just 7 1/3 innings, which led to his initial demotion to Reno in mid-April, during which he had an ERA of 15.95. After a brief recall where he surrendered four more earned runs in 2 1/3 innings, he was sent back down, leaving him with an alarming 15.83 ERA in a total of 9 2/3 innings pitched this year.
Underlying Issues Contributing to Mantiply’s Struggles
Part of Mantiply’s difficulties stem from bad luck; his batting average on balls in play (BABIP) stands at an unusually high .512, and his strand rate—a measure of runners left on base—is just 56.5%, both signaling unfavorable circumstances. Still, his strikeout rate has sharply declined to 13.8% this season, and his ground-ball rate has fallen to 43.2%, reducing his effectiveness overall.
Implications of the Designation for Assignment
Designating Mantiply for assignment removes him from the Diamondbacks’ 40-man roster and opens a spot for roster flexibility. The DFA period provides the team up to seven days to complete a trade, release him, or send him outright to the minors if he clears waivers. The waiver window lasts 48 hours, during which the Diamondbacks will assess potential interest from other Major League Baseball teams.
Teams are often hesitant to absorb salaries midseason, even modest ones, which complicates finding a trade partner. For context, left-hander Joel Payamps, with a troubled season similar to Mantiply’s, recently cleared waivers without a claim from any club, largely due to concerns over his remaining $2.995 million salary.
Mantiply’s Contract and Future Prospects
Mantiply’s 2025 salary is $1.7 million, less than Payamps’ but still a factor. As a lefty with remaining minor league options, Mantiply presents more flexibility for interested teams, though he is three years older. Should he go unclaimed, Mantiply will likely remain with the Diamondbacks organization in a non-roster capacity to provide depth.
Players with more than three years of major league service, like Mantiply, have the right to reject an outright assignment and become free agents. However, with fewer than five years of service, electing free agency requires forfeiting remaining salary, making acceptance of a minor league assignment more probable under current conditions.
Outlook for Mantiply and the Diamondbacks Moving Forward
The coming days will be pivotal in determining Mantiply’s immediate future, whether another MLB team claims him or the Diamondbacks retain him off the 40-man roster. The decision underscores the Diamondbacks’ efforts to adjust their roster amid ongoing performance concerns and maintain competitive depth.