If during a word association game prior to the season, you had said “stopgap first baseman,” I almost certainly would have answered with “Mitch Moreland.” Never amazing but also rarely terrible, Moreland has been a fixture as the long-term/short-term first baseman for Boston the last four seasons. Peaking at 2.2 WAR for the 2015 Rangers, he’s put up between 0.7 and 1.0 WAR in six other seasons, building a handy little pillow fort between average and replacement level.
And while Moreland is unlikely to ever finish among the league leaders in home runs, he has become quite good at harvesting pitchers’ regrets. Statcast defines “meatballs” as middle-middle pitches; an average hitter swings at about 75% of those. Moreland’s rate is at 87.3% in 2019 and 2020 combined, meaning he’s only half as likely as the typical player to leave his bat on his shoulder for those pitches. Here’s his radial chart against middle-middle over those two seasons:
Even if his wRC+ drops from his currently lofty 203, ZiPS has seen enough from Moreland to give him a rest-of-year projection of a 119 wRC+, which would be the best for any single season of his career to date.
The Padres are serious playoff contenders, so it makes sense for them to value certainty more than long-term upside and Moreland fits the bill at DH. The team’s already down one hitter due to Tommy Pham‘s broken hand and Moreland represents a significant upgrade over the team’s 2020 DH usage so far, which has generally consisted of resting players and, most recently, Ty France and Greg Garcia. I like Josh Naylor in the long run, but Moreland is better right now, and right now is what’s most important for San Diego. Moreland’s contract comes with a $3 million team option for 2021, adding to his value should the Padres try to move him after the season if pitchers resume hitting in 2021, the odds of which I feel are less than 50/50.
Boston’s 2020 fate wasn’t sealed with the disappointing trade of Mookie Betts, but after more pitcher injuries, including the loss of Chris Sale, J.D. Martinez‘s struggles, and an 11-22 record, it is now. Moreland had significant value to a Boston team fighting for one of the back-end playoff seeds; he has much less with the Red Sox hanging out in the American League’s basement. While Boston is likely to retool this offseason and be at least a legitimate Wild Card contender in 2021, it’s hard to turn down adding Potts and Rosario, particularly given how thin Boston’s system is.
Potts, a first-round pick from 2016, hasn’t exactly lit up the minors, hitting .256/.315/.428 in parts of four seasons with 463 strikeouts in under 2000 plate appearances. The contact issues are concerning, but my colleague Eric Longenhagen is less worried, telling me he’s “not as scared of Potts’ upper-level swing-and-miss issues because he’s been the age of a college hitter playing Double-A and Triple-A ball.” Eric sees Potts on the 1B/3B defensive fringe (see: Ron Coomer) with his possible future role being that of a backup at the corner infield and outfield positions. ZiPS sees Potts similarly, projecting him to have a legitimate career, with “role player” as the mean expectation:
A lot of the players in Potts’ ZiPS comps fulfilled this exact role, with names like Greg Norton, Jeff Manto, Scott Coolbaugh, Shane Andrews, and Craig Worthington likely to be at least vaguely familiar to most people reading this article. There is some upside here — enough that ZiPS just squeezed him into its Top 100 — so I don’t want to sound unduly negative. The projections are actually a bit worse in Fenway, which the computer sees as a poor park for him, given that it tends to favor ball-in-play guys over high-strikeout power hitters.
As for Rosario, Eric noted that he has one of the weirder profiles out there, being an elite athlete who could potentially have elite plate discipline skills, but without much power. It’s hard to ignore that last bit as the minor leagues are strewn with players who are plate discipline gods at the lower levels, but are unable to maintain that against the better pitchers in the upper-minors and majors.
ZiPS currently sees Rosario with a .220/.330/.300 peak, which might get him some cups of coffees if he has significant defensive value, but not much more than that. Today’s game obviously features a lot more power than it did in, say, the 1980s, but one of the differences now is that every position hits for power. Center fielders in both 2019 and 2020 averaged 20 home runs per 600 plate appearances and that’s all center fielders, not just the starters. Jarrod Dyson strikes me as a reasonable upside scenario for Rosario, but remember that Dyson slugged nearly .350 in the minors in a somewhat worse offensive environment and he still wouldn’t have gotten the chances he did if he hadn’t been such a stupendous defensive player.
Both Potts and Rosario have to be added to the 40-man roster this winter or be exposed to the Rule 5 draft. The Padres are a far deeper team than they were a few years ago and as contenders, it would have been hard to add even one to the roster let alone both, a situation further complicated by the fact that like most minor leaguers, both are essentially missing a year of experience. Moreland is a better return than the token sums received as Rule 5 compensation.
This trade gets a thumbs-up from me for both sides. Boston got the best possible return I can imagine for Moreland and the Padres got a fastball-crushing designated hitter to add to the party in Slam Diego.
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Dan Szymborski is a senior writer for FanGraphs and the developer of the ZiPS projection system. He was a writer for ESPN.com from 2010-2018, a regular guest on a number of radio shows and podcasts, and a voting BBWAA member. He also maintains a terrible Twitter account at @DSzymborski.