Earlier today, the Philadelphia Phillies and Milwaukee Brewers made a swap ahead of this year’s 40-man roster deadline, the last day teams have to either add eligible minor league players to their 40-man roster or expose them to December’s Rule 5 Draft. In this trade, the Brewers acquired 26-year-old second baseman Oliver Dunn and added him to their 40-man roster, while the Phillies received two prospects in return, 21-year-old infielder Robert Moore and 20-year-old outfielder Hendry Mendez.

Let’s start with Milwaukee’s end of this, as we’re most likely to see 2024 big league impact from Dunn, who is coming off an Arizona Fall League stint in which he won the league’s Breakout Prospect award. Dunn, whose brother Ross is in the Twins system, was a Yankees 2019 11th round pick out of Utah. He hit .196 coming out of the lost 2020 season, and spent a significant portion of both 2021 and 2022 on the IL dealing with multiple injuries, including a fractured jaw, an abdomen strain, and a hamstring strain.

The Phillies drafted him in the minor league phase of the 2022 Rule 5 Draft and Dunn had a huge power breakout in 2023 at Double-A Reading, where he hit .271/.396/.506 and slugged 21 homers, more than he had hit throughout his entire career entering 2023. Reading is a hitter’s haven and Dunn was in his age-25 season, so there are good reasons to be skeptical of his sudden change in output, but his underlying power metrics also took a leap, with his average and peak exit velocities (92 mph and 112 mph, respectively) cresting above the big league average. This isn’t gigantic, impact power, but it’s meaningful pop for a second baseman. Dunn swings and misses quite a bit, especially within the strike zone (you can see him struggling with velo up and away from him, a Fall League theme for Dunn, in the video below), but he’s a dangerous all-fields hitter because of his power and ability to catch some fastballs deep in the hitting zone and punish them the other way.

Dunn isn’t an especially good defensive second baseman, nor is he versatile. He has spent a little bit of minor league time at third base (including five AFL games) and in left field, but his lack of mobility and arm strength make him a below-average, second base-only defender in my eyes. This lack of versatility is the biggest barrier between Dunn and 2024 major league playing time. If Willy Adames is traded this offseason and Brice Turang moves to shortstop, then Dunn fits as a lefty-hitting complement to Owen Miller, Andruw Monasterio and the other righty-hitting infielders on Milwaukee’s 40-man. He’s in better position for reps than Vinny Capra, Jahmai Jones and arguably Miller just by virtue of his handedness. I have him evaluated as an above-replacement player but not one of big impact, similar to Cavan Biggio without plate discipline quite as good.

In return for Dunn, the Phillies acquired two prospects who had “stock down” seasons in Mendez and Moore. Regardless of that, it’s evidence of good scouting and process for an org to flip a minor league Rule 5 pick for multiple prospects in less than a year, so this deal is a feather in the cap of the Phillies despite these two players having had rough 2023 seasons relative to my expectations. Mendez was a 2023 Pick to Click who didn’t click. He has been a fascinating young prospect since debuting in the U.S. in 2021 as a 17-year-old with very precocious feel for contact despite a strange swing path that led to an inordinate number of groundballs. Even though he’s filled out and gotten stronger during the last few years, Mendez hasn’t been able to actualize any more power in games. His body and swing looked stiffer than usual in the 2023 Fall League. As a corner-only defender, he needs to produce more in-game power than he has to this point if he’s going to be a big leaguer. Exciting feel for contact is still here, but Mendez’s swing is so long and bottom-hand driven that he probably needs an overhaul to succeed against upper level pitching in this regard. A change of scenery might enable this, but he’s going to be toward the very bottom of the Phillies prospect list with his skills as they’re currently constituted.

Moore has been a known prospect since his underclass high school days, and he ended up matriculating to college early in order to be an extremely young (20.3) junior for his draft year. The apex of Moore’s stock came while he was a sophomore at Arkansas, when he looked like a potential top 10 or 15 pick for the following year’s draft. He had a substantial downtick in performance as a junior and there was a rumor at the time that he might go back to school to try to recoup some draft helium with an age-21 senior season. Instead Moore signed with the Brewers for $800,000 as a second rounder. He spent 2023 at High-A Wisconsin, where he slashed .233/.321/.361. Plus actions and advanced defensive acumen are now his carrying tools and enable him to project as a viable defender at both middle infield positions. The tiny Moore struggles to hit for power and has some plate coverage issues from the left side, struggling to contact pitches on the outer third. A bounce-back candidate for the last year and change, I now see him as having more of a utility ceiling.

Not only was Bryson Stott blocking Dunn, but Rodolfo Castro and Kody Clemens each have a similar profile but with louder tools. Both Mendez and Moore have 2025 40-man roster timelines, so the team has two full years to develop them further before either can be considered on deck to contribute in Philly. Dunn’s power gives him a bigger ceiling than I’d forecast for either Mendez or Moore, despite those two each being at least five years younger than Dunn, but if Dunn isn’t going to be an everyday second baseman, he has to become a viable defender at at least one more position to play any kind of meaningful role for Milwaukee.