How a Surprising Defensive Shift Is Changing the Game Overnight

Roster Improvement

There was always going to be at least some defensive regression by swapping Josh Naylor for Christian Walker at first base. While Naylor isn’t bad in the field – he clocked in at 13th in the league with 1 outs above average (OAA) in 2024 – he’s nowhere near the 13 OAA that Walker produced that year. Ironically, Walker took significant steps back both offensively and defensively last year – enough that he and Naylor were on par with one another for defensive value. Now that Naylor’s found his new home in Seattle (with his distractingly cute dog), the D-Backs needed another first baseman alongside Pavin Smith – enter Carlos Santana. While Santana’s most significant offensive contributions are likely behind him in his improbably long-lasting career, he and his 8 OAA represent significant improvements defensively over Naylor – and don’t forget (like I did) that he’s just two years removed from a Gold Glove-caliber season at the cold corner. On the diagonal side of the diamond, Nolan Arenado has long been a defensive wizard at the hot corner even as his contributions at the plate continue to decline with age. Contrastingly, Eugenio Suarez has been a minus-defender at third base for most of his career – including leading the league in errors in two separate seasons. That’s perfectly fine when he’s hitting four home runs in a game, but becomes less acceptable when he posts a measly .189/.255/.428 slash line. It’s a deliberate choice by the front office to trade offense for defense while banking on the combination of Geraldo Perdomo, Ketel Marte, and Corbin Carroll to pick up the offensive slack. That’s an understandable and perhaps worthwhile exchange, but it’s a bet predicated on that aforementioned trio maintaining their respective offensive ceilings – a bet that may be in danger already given Carroll’s hamate injury.

Individual Improvement

While the roster changes above should, on paper at least, improve the team’s defense, they alone likely still won’t allow the team to reach the heights they hit during that 2023-24 stretch. For that to happen, they’ll likely need some growth from some of their existing players – particularly the younger ones that are still looking to fully establish themselves. In my mind, this dynamic particularly applies to Perdomo and Gabriel Moreno. Last season was undoubtedly Perdomo’s unexpected (for me at least) breakout from solid major leaguer to legitimate star. And while he was good in the field, checking in at 16th for defensive WAR among shortstops last year and accumulating 5 OAA, there might still be room for improvement as he continues to gain confidence and additional comfort at the position. There probably isn’t as much room for improvement for Moreno who has been an absolute beast defensively since coming over from the Blue Jays in the 2022-23 offseason. For the young Venezuelan, it has more to do with his durability and ability to stay on the field as he’s played in 100 or more games just once – back in his inaugural season with the team. Obviously, catching is an inherently difficult and physically taxing position and the number of catchers who exceed that threshold isn’t incredibly long, but it is important. Sadly, Moreno has been absolutely snakebitten (pun intended) with injuries, losing time due to shoulder inflammation (three weeks), a thumb sprain (ten days), an adductor strain (six weeks), and last year’s finger fracture that ultimately cost him two-plus months of playing time. When he’s on the field, he can be a dynamic game changer with his bat and his arm cutting down baserunners – it’s just the first part that has been a struggle.