You thought we need a lot of starting pitching? Wait till you get into the bullpen. All told, the Diamondbacks used THIRTY different relievers this year. It’s only the second time Arizona has needed more than twenty-five, the other time being for the post-COVID campaign of 2021, when a mind-numbing 35 relievers were used. [Of the ten times in baseball history a team has needed 35+ bullpen arms in a season. six came in that year, include the all-time mark of 38 by the Orioles] Now, that number does include Jose Herrera, Carson Kelly, Josh Rojas and Seby Zavala, who worked a total of 6.2 mop-up innings. But that still leaves twenty-six “legitimate” relief arms who pitched for the D-backs last year.
I will not attempt to list 26 names who might be in the Arizona bullpen this year. If I’d done the same exercise at this point last year, I’d probably have missed on half or more of the names, for reasons both good (Paul Sewald, Ryan Thompson and Andrew Saalfrank) and bad (Nabil Crismatt, Peter Solomon and Cole Sulzer). But there were sixteen pitchers who worked ten or more games in relief for the Diamondbacks, as good a place to start as any. There are several names we can cross off. Austin Adams, Andrew Chafin, Tyler Gilbert and Jose Ruiz are no longer in the organization, Drey Jameson will likely miss the entire season due to Tommy John, and Bryce Jarvis is more likely a starter. That leaves us with ten.
We already discussed the closing situation, with Paul Sewald and Kevin Ginkel likely to be the tip of the spear in terms of high-leverage work. Let’s call that pair Tier A. Tier B are the pitchers who have a track record, who will also be looked at to get big outs in key situations, and seem to have bullpen slots locked up as we go into spring training. Those are Miguel Castro, Scott McGough and Kyle Nelson. Between them, they appeared more than two hundred times in 2023, though Castro in particular received a lot of flak from fans. It’s understandable. He had a brutal month just after the All-Star break where he went 0-3 with two blown saves over 14 appearances, with a 12.27 ERA.
It wasn’t long after this spell that Castro hit the 60 appearance mark, where his $5 million option for 2024 became locked in, to Twitter’s unhappiness. But then, he either fixed himself, or the wheel o’ reliever volatility spun the other way, because from August 21 through the end of the regular season, he had a 1.26 ERA in 18 games. His post-season work was inconsistent, in particular taking the loss in Game 1 of the World Series without recording an out. That didn’t help fan sentiment, shall we say. But if you took the name away from the stats - albeit cherry-picked ones - then as Michael showed in December, almost everyone is back on Team Castro for 2024.
If the #Dbacks could add a bullpen arm that in 2023...— Michael McDermott (@MichaelMcDMLB) December 24, 2023
81% of appearances scoreless
79% of appearances with positive WPA
72% of inherited runners stranded
Averaged 97 MPH on his fastball
xERA of 3.82
And the cost was around $5 million dollars, would you do it?
That likely leaves three bullpen spots, presuming a 13/13 split on the roster between position players and pitchers. Tier C are those who have tenure to whatever degree, and should perhaps be considered as the current front-runners for those places. For now, I think those belong to Joe Mantiply, Andrew Saalfrank and Ryan Thompson. However, it will be interesting to see if the team wants to go with three southpaws, and keep both Mantiply and Saalfrank in addition to Nelson. They did in 2023 - but only in September and the post-season, when rosters expanded and fewer starters were needed. Mantiply’s season was hampered by injury, but he was fine on his return.
If you only saw Thompson’s games with Arizona, where he allowed one run over 13 innings, with a K:BB of 9:1, you’d be forgiven for wondering why he’s not in Tier B. It’s because as he good as he was, he was as bad early on with Tampa: a 6.11 ERA and 12:7 ratio over 17.2 IP there. As ever, the reality is likely somewhere in the middle. His career ERA is 3.57 with a FIP of 3.73, and that’s about what I’d expect. It’s an ERA+ of 113, which is pretty decent for someone projected to earn $1.3 million in arbitration for 2024. However, if the uptick proves to be the result of the Strom Effect, Thompson could end up getting promoted to a higher tier during the season.
Tier D are those who may or may not make their way onto the Opening Day roster, but are likely to see action at some point in the season. How much, and where they end up, depends entirely on them. The most intriguing name is Justin Martinez, the hardest thrower in franchise history. His fastball averaged 100.5 mph, topping out at 102.7 mph. When on, he could be awesome, as when notching his first save against the Padres. But along with his 14 strikeouts in 10 innings, came 11 walks, and the rates were much the same in the minors. If he can locate better, then he could end up fighting with Ginkel for the closer’s spot in 2025. That’s by no means certain, however.
Others in this tier are those already on the 40-man roster, who can be used without the need to clear space. They include Luis Frias (the tenth and last of the 10+ games in 2023 group, and so perhaps the biggest initial threat to the Tier C pitchers), Collin Snider and Peter Strzelecki. In addition to Frias, Strzelecki appeared for the D-backs last year, though if you blinked you’d have missed Peter’s sole appearance, after being traded from the Brewers for Andrew Chafin. The way Chafin pitched in Milwaukee, this deal was a win for Arizona, simply through Strzelecki not being Andrew Chafin. However, I hope he doesn’t make the roster, purely for selfish reasons, because I’m never going to be able to spell his name...
Finally, in Tier E, will be the non-roster invitees who get an invite to spring training. As with the starting pitchers, those will be a mix of experienced veterans who aren’t good enough to get a guaranteed major-league contract, and up and coming prospects who didn’t need to be added to the 40-man roster this winter. We don’t have many names yet, except for Jose Castillo. He has pitched a total of two (2) major-league innings over the last five seasons. I feel that Tier E is probably safe for him. I do expect further names to arrive. Last year, there were 28 non-roster invitees, with Austin Adams the most-used reliever off that list. We should know more around the beginning of February.
To summarize for now, here’s what we have.
Jose Castillo and the field