Zac Gallen

The Diamondbacks’ surprise signing of Corbin Burnes further crowded a rotation that had at least six starters in the mix. While there’s been talk of a possible six-man rotation in Arizona since that Burnes deal, manager Torey Lovullo said at D-backs camp this week that team is not considering that at this point (link via Nick Piecoro of the Arizona Republic).

That leaves the Diamondbacks with seven starters for five spots: Burnes, Zac Gallen, Merrill Kelly, Eduardo Rodriguez, Brandon Pfaadt, Jordan Montgomery and Ryne Nelson. The first four are largely locked into place. Burnes and Gallen are Cy Young-caliber arms when healthy. Kelly has been a steady midrotation arm for the Snakes since signing out of the KBO in the 2018-19 offseason. Rodriguez’s first year in Arizona was marred by injury, but he’s signed three more years and has a lengthy track record.

Montgomery’s status in Arizona has been a talking point throughout the winter. The Diamondbacks signed him to a one-year, $25MM contract with a vesting $20MM player option for the 2025 season. The left-hander pitched enough to trigger that option but nowhere near well enough to decline it in favor of a return to the open market. Signing just days before Opening Day last season, Montgomery missed spring training, rushed through an accelerated ramp-up in Triple-A and never appeared to be himself. He pitched 117 innings but was rocked for a 6.23 earned run average with career-worst walk and strikeout rates.

D-backs owner Ken Kendrick called Montgomery’s performance out late in the season, publicly lamenting the role that he’d played in bringing the left-hander to his organization. “I brought it to (the front office’s) attention. I pushed for it,” Kendrick said in September. “They agreed to it. It wasn’t in our game plan. … And looking back, in hindsight, a horrible decision to have invested that money in a guy that performed as poorly as he did.”

Pfaadt, 26, would give the D-backs an upside arm at the back of the staff. The former top prospect hasn’t yet found his stride over a full big league season but has shown glimpses of the potential that made him so well regarded. He looked to have found his stride last year, logging a 3.98 ERA, 23% strikeout rate and 4.9% walk rate through his first 24 starts, but Pfaadt was hit hard in late August and for much of September. He mixed in one late-season gem — seven innings, one run, 12 strikeouts in Milwaukee — but even with that showing still posted an ERA north of 7.00 over his final eight starts. He finished the year at a 4.71 mark but did pile up 181 2/3 innings.

Nelson, who turned 27 in December, made 27 appearances this past season — 25 of them starts — and recorded 150 2/3 innings of 4.24 ERA ball. His 20% strikeout rate and 8.4% swinging-strike rate were below average (well below, with regard to the latter), but Nelson’s 5.4% walk rate was outstanding.

There are other options on the 40-man roster, but they’re likely to be viewed as depth candidates, barring a spring breakout. Yilber Diaz, Cristian Mena, Tommy Henry and Blake Walston are all on the 40-man roster and have all made their big league debuts, but they’d likely only be called upon in the event of multiple injuries — at least with the current roster construction.

Kendrick’s comments on Montgomery led to plenty of speculation about a potential trade of this winter, but no such deal has come to fruition. It’s still possible the D-backs could find a taker for a portion of the contract or swap him out for a comparably priced veteran on an underwater deal (e.g. Rhys Hoskins, Starling Marte), but for now, Montgomery will get a full spring buildup and look to bounce back from a dismal 2024 season.

If the D-backs can find some kind of trade that sheds a portion of the Montgomery money, any savings could be reallocated to other needs. Most notably, they’ve been in the market for a closer throughout the winter but have yet to add an established ninth-inning arm. Arizona’s payroll is projected for a franchise-record $195MM, per RosterResource. It’s not clear whether Kendrick is willing to push things further after already ponying up to sign Burnes (six years, $210MM), acquire Josh Naylor in a trade (one year, $10.9MM) and re-sign Randal Grichuk (one year, $5MM). Barring the signing of a veteran like David Robertson or Kyle Finnegan, the D-backs will look inward and lean on A.J. Puk, Justin Martinez and Kevin Ginkel as their top late-inning arms.

The Diamondbacks’ surprise signing of Corbin Burnes added a new frontline arm to a rotation that was already operating at a surplus on paper.  Burnes joins Zac Gallen, Merrill Kelly, Eduardo Rodriguez, Jordan Montgomery, Brandon Pfaadt, and Ryne Nelson, giving the Snakes an enviably deep group of starting pitchers.  The D’backs had already been drawing trade interest in this group even before Burnes was added, but Nick Piecoro of the Arizona Republic reports that the Burnes signing wasn’t made with any other pitching swaps immediately on the horizon.

According to Piecoro, no “other deals [are] lined up or even close” involving Arizona’s pitchers, as the Diamondbacks will continue to take a measured view of the market.  A source tells Piecoro that the D’Backs will likely “spend the coming days fielding calls from teams still in the hunt for starters, including those that were in on Burnes.”  The D’Backs aren’t in any particular rush to complete a trade any time soon, as having more than a full rotation in place before New Year’s Eve gives the club plenty of time to figure out the best possible offer.

It also isn’t entirely out of the question that the Diamondbacks stand pat on their starters, especially if an injury emerges to a starter during their offseason training, or during Spring Training.  Kelly, Rodriguez, and Montgomery all missed significant time with injuries last season, so there is obvious value in having extra pitchers on hand should any more health issues create openings in the rotation.  Operating with a six-man rotation is also a possibility, in order to keep everyone healthy and fresh for what the D’Backs hope can be an extended run through the playoffs.

Given how the Burnes deal reportedly came together just within the last week when Burnes himself approached the D’Backs, it isn’t surprising that the signing wasn’t part of an immediate plan to re-model the pitching staff.  Such two-step transactions are usually hard to pull off, though the Diamondbacks were part of such a set of moves from the Guardians just last week — Arizona acquired Josh Naylor from the Guards, and Cleveland then signed Carlos Santana that same day to immediately fill Naylor’s spot as the everyday first baseman.

The fact that Burnes signed with a team that was seemingly already set for starting pitching gives GM Mike Hazen even more leverage in shopping his hurlers.  Such known Burnes suitors like the Orioles, Blue Jays, or Giants are still in need of pitching, to say nothing of the many other starter-needy clubs on the market that weren’t willing or able to meet Burnes’ asking price.

Nothing seems to have changed in terms of which starters are most prominently on Arizona’s trade block.  Gallen and Kelly are both free agents next winter but don’t seem likely to be dealt, as a team source told Piecoro that the team’s focus in on “trying to put the best team on the field in 2025.”  Nelson is controlled through the 2027 season and Pfaadt through the 2029 season, so the Diamondbacks would probably only move either if a longer-term asset (likely a position player) could be obtained in return.  The D’Backs might not mind moving the $66MM remaining on Rodriguez’s contract, but the club would certainly have to sell low and eat some of that money in the wake of E-Rod’s injury-plagued down year.

That leaves Montgomery as still the chief candidate to be dealt before Opening Day.  Montgomery’s trade value is also at a low ebb after his rough first year in Arizona, and his $22.5MM salary for the 2025 season.  Owner Ken Kendrick’s public criticism of Montgomery following the season only increased the probability that the left-hander would be pitching elsewhere next year, yet again, the Burnes signing gives the D’Backs some flexibility in this regard.  The Diamondbacks technically don’t have to trade Montgomery if an acceptable offer for another starter comes their way, and offers for Montgomery might improve if other teams become increasingly desperate to add pitching.