Diamondbacks Option Struggling Lefty Reliever to Triple-A

Joe Mantiply has been optioned to Triple-A Reno, per the Diamondbacks' transaction page. No corresponding move has been announced, as the team is off on Thursday before taking on the Colorado Rockies for Rivalry Weekend at Chase Field.

Mantiply, 34, was originally expected to be a big part of the Arizona bullpen. Instead, he's been one of the poster children for the unit's struggles over the past four weeks. In 10 appearances, he's 0-1 with a 15.83 ERA.

After starting the season with three scoreless appearances out of four, Mantiply has allowed runs in six consecutive appearances. Over that stretch, he's surrendered 14 runs on 22 hits, three walks, and four strikeouts over 6.1 innings. Opposing hitters are batting .550 with a 1.541 OPS.

Mantiply was previously optioned on April 19, as the Diamondbacks needed to get fresh arms into their bullpen, but was recalled to the major league roster on May 10. He surrendered home runs to Freddie Freeman and Jung-Hoo Lee in his two appearances since.

With two open spots on the 40-man roster and multiple options remaining, there is no urgency for the team to cut bait with the struggling left-hander. However, his performance underscores a tough reality with the team's left-handed reliever depth since A.J. Puk was placed on the injured list on April 19.

Even though Jalen Beeks has been a godsend for this bullpen, the other left-handers have struggled over that stretch. José Castillo and Mantiply have combined to allow 15 runs on 22 hits in 9.1 innings since April 18.

The Diamondbacks have plenty of options they can go to replace Mantiply on the 40-man roster. Barring an injury, Tommy Henry, Scott McGough, and Cristian Mena are not eligible to be recalled to the active roster from Reno for this upcoming series. On their 40-man roster, they could turn to Yilber Díaz or Drey Jameson, although both pitchers mightily struggled in their last outing.

Alternatively, they could turn to right-hander Kyle Amendt or left-hander Kyle Backhus to fill the spot in the bullpen. Amendt and Backhus both have sub-3.00 ERAs with Reno, with solid strikeout numbers. With two open spots on the 40-man roster, they can just select them and add them to the active roster.