Diamondbacks designate struggling pitcher for assignment

The Diamondbacks announced a series of roster moves on Friday, most of which were previously reported. They have selected right-hander Jeff Brigham and signed infielder Ildemaro Vargas. To open active roster spots for those two, infielder Jordan Lawlar and right-hander Kevin Ginkel have been optioned to Triple-A Reno. The club had one open 40-man roster spot but opened a second by designating left-hander Joe Mantiply for assignment.

Mantiply, 34, has fallen on hards time here in 2025 after a strong performance in previous seasons. From 2021 to 2024, he logged 198 1/3 innings with the Diamondbacks, allowing 3.63 earned runs per nine. His 22% strikeout rate in that time was around average but he only walked 6% of batters faced and kept 51.9% of balls in play on the ground. He racked up three saves and 50 holds in that span.

But this year, he allowed 13 earned runs in his first 7 1/3 innings. He was optioned down to Reno in mid-April while sporting an ERA of 15.95. He was recalled briefly a couple of weeks ago and allowed four more earned runs in 2 1/3 innings before getting optioned down again. He currently has an ugly 15.83 ERA on the year, though in a small sample of 9 2/3 innings.

There’s surely some bad luck in there, with his .512 batting average on balls in play and 56.5% strand rate both far to the unfortunate side of things. However, his strikeout rate has also dropped to 13.8% this year, and he’s only been getting grounders at a 43.2% clip.

Those struggles have apparently been enough for him to lose his 40-man spot. He now heads into DFA limbo, which can last as long as a week. The waiver process takes 48 hours, so the Snakes could spend up to five days exploring trade interest.

Other clubs might be willing to look past this year’s struggles, but MLB teams are generally loath to take on money via midseason pickups, even relatively small amounts. Joel Payamps, like Mantiply, is a pitcher with some recent success but is having a bad year. He recently passed through waivers, with no club willing to take on what remains of his $2.995M salary.

Mantiply is making $1.7M this year, barely half of what Payamps is making. He is also left-handed and can be optioned to the minors, whereas Payamps is a righty and out of options. On the other hand, Mantiply is three years older. The next few days will tell if Mantiply can find a club willing to take him on.

If he goes unclaimed, he will likely stick with the D’Backs as non-roster depth. Players with at least three years of major league service time have the right to reject an outright assignment and elect free agency. However, players with less than five years of service have to forfeit any remaining salary in order to exercise that right. Mantiply is shy of the five-year mark and would therefore probably accept an outright assignment, in order to keep that salary coming to him.