Postseason reveals what the Arizona Diamondbacks need to work on this off-season

This year's Postseason has revealed what the Arizona Diamondbacks must do this off-season to improve in 2024.
Oct 31, 2023; Phoenix, Arizona, USA; Arizona Diamondbacks starting pitcher Joe Mantiply (35) reacts
Oct 31, 2023; Phoenix, Arizona, USA; Arizona Diamondbacks starting pitcher Joe Mantiply (35) reacts / Joe Camporeale-USA TODAY Sports

The Arizona Diamondbacks have made baseball’s biggest stage, the World Series, but it’s not been on the backs of their starting pitching depth. They’ve been riding on the arms of Brandon Pfaadt, Merrill Kelly, and Zac Gallen as their primary starting pitchers. Pfaadt and Kelly have more than held their own this Postseason, giving the Diamondbacks a few quality starts. But Gallen has struggled.

So far, they’ve used Joe Mantiply as an opener twice, and it didn’t go smoothly either time they tried to bullpen a playoff game. But this Postseason shows what the D-Backs need to fix most this off-season, and that’s adding more starting pitching, as well as pitching depth.

The rotation is headlined by a solid trio of Zac Gallen, Merrill Kelly, and Brandon Pfaadt, but it is not a deep group. The Diamondbacks’ farm system also doesn’t present a higher-end near-MLB-ready option. Slade Cecconi is a potential option for 2024, and while he didn’t do horribly in the ultra-hitter-friendly PCL, he’s about the only thing in the system in terms of starting pitching.

Regarding potential starting pitching options who already appeared in the majors, Tommy Henry likely would have secured a playoff roster spot had it not been for an elbow injury. This injury likely is the reason the D-Backs have had to bullpen two games now. As long as Henry is healthy going into 2024, he’ll have the inside track on one of the last rotation spots. That leaves the number five rotation spot up to Ryne Nelson. Nelson had both an ERA and FIP over 5.00 and struggled badly down the line. He was included on the D-backs’ Postseason roster but has only been used in low-leverage out of the bullpen. He has made all of two appearances.

The Diamondbacks must pursue the starting pitching market this off-season. Could we see them pull another Zack Greinke and sign one of Sonny Gray, Blake Snell, Jordan Montgomery, or Aaron Nola to a five-plus year deal with an AAV over $20 million? Maybe they get ultra-aggressive and go after one of the top international pitchers, namely Yoshinobu Yamamoto or Shota Imanaga.

Even if the Diamondbacks only go for a mid-tier option, like Kenta Maeda, Lucas Giolito, Jack Flaherty, Michael Lorenzen, Wade Miley, Mike Clevinger, or Hyun-Jin Ryu, what matters the most is that they solidify their rotation with reliable pitchers.

On top of that, they need depth too. What would be the fallback option if Pfaadt were to miss multiple weeks? Then who steps into the rotation? Is Nelson going to be their best #6 starter option? Of course, it’s unrealistic to expect a team to have seven quality starting pitcher options. But maybe a decent hybrid starter/reliever should be on the checklist, such as Jakob Junis, along with at least one quality starting pitcher.

Whatever the option the Diamondback chose this off-season, they need to add both at least one good starting pitcher and some decent depth behind it. They need to have five established starting pitchers, as well as a few potential fallback options in the event a pitcher struggles or if there is an injury.