D-backs 2023 Starting Rotation May Heavily Depend on Rookies

With a bevy of big league ready arms, Arizona may depend on rookies to fill holes in the rotation next season.

The Diamondbacks rotation features a pair of solid arms at the top in Zac Gallen and Merrill Kelly. Gallen is coming off a sensational second half and Top 5 Cy Young finish while Kelly enjoyed a career year. Both players have a long track record of being reliable starters in the big leagues, but after those two there is a lot of uncertainty between an underperforming starter and a bevy of big league ready pitching prospects that could arrive in 2023.

At the start of the season, the D-backs will look to Madison Bumgarner to fill out a rotation spot hoping to salvage his career. Worst case scenario he'll get five to seven starts to prove he can be a capable starter, so they'd need someone to cover the rest of the season if Bumgarner is released or goes on the injured list. In his WAR and payroll update article, Jack Sommers projects Bumgarner to pitch 115 innings for the D-backs in 2023. That leaves two rotation spots open for competition next spring, as the team has two options they can go to in order to fill them. They can hope the farm system can produce two big league starters or they can target a starting pitcher from the free agent or trade market. 

The farm system has four pitching prospects who could make a run at a rotation spot between Brandon Pfaadt, Drey Jameson, Ryne Nelson, and Tommy Henry. Jameson, Nelson, and Henry have already gotten their feet wet at the big league level and Pfaadt is the reigning Minor League Pitcher of the Year in the organization. In the postseason media day, general manager Mike Hazen stated he was comfortable potentially starting two rookies in next year's rotation and they wouldn't necessarily aggressively chase. Jameson, Nelson, Henry, and Pfaadt all pitched over 150 innings, so a full-time starter workload of 165-180 innings isn't a big jump for them. 

The D-backs could either leverage their outfield surplus or look to the free agent market to acquire a starting pitcher. The upside to picking up a veteran starter is their production on the mound will be less volatile, which can be easier for a manager to get through a game. However the downside is they may spend money on a less productive player than what the farm system can produce. With the D-backs operating on a tight budget compared to their division foes, they'll need to capitalize on the value of the farm system and convert that to wins. 

Most of the top tier starters have already been plucked from the free agent market. The D-backs aren't currently linked to any starting pitcher in the free agent or trade market, although most likely a few names came up in discussions for the team's outfielders on the trade block. This will likely be a situation where the team waits for the dust to settle on the market and makes an attempt at a bounceback candidate to try to eat up some innings for them in a short term deal. That is a similar move to what they did last year when they signed Zach Davies to a one-year deal. 

Should the D-backs decide that the free agent and trade market is too cost prohibitive to add a starting pitcher, they will likely rely on at least two pitchers from their farm system to eat up a significant number of innings. In his playing time projections, Sommers has Jameson, Pfaadt, and Nelson combining for 320 innings out of the rotation in 62 starts. Add in four starts from Blake Walston and five from Slade Cecconi, the team is looking at over 40% of their starts coming from rookies. Depending on how well Bumgarner, Jameson, Pfaadt, and Nelson pitch in 2023, that number could drastically increase.