How does Steve Pearce fit on the Red Sox roster?

Shortly after the Red Sox finished off a sweep of the season series against the Angels on Thursday night, Dave Dombrowski pulled off his first trade of the 2018 season. In the deal, he sent out Santiago Espinal to Toronto in exchange for Steve Pearce. We had known for a couple weeks now that one of the areas the team was hoping to address over the next month was right-handed hitting depth, and they had even been connected to Mark Canha not too long ago. That didn’t end up being the deal they pulled off, but they filled the hole by acquiring Pearce. Now that the move has been made, the question becomes how the newest member of the Red Sox fits on his new roster.

The first question is simply how Boston gets Pearce on to their active roster. As we mentioned when the deal first went down, the Red Sox don’t have a major headache on their hands in this respect. The team has been carrying only 39 players on their 40-man roster, so they do not need to do anything too drastic to make room for Pearce. For example, it is not necessary to find a solution to the Blake Swihart issue at the moment. It is worth mentioning, however, that Sean McAdam reported Thursday night that the team is exploring trade possibilities for their former top prospect. Regardless, the easy and likely move will be to demote Tzu-Wei Lin back to Pawtucket and slide Pearce into his active roster spot as well as the open 40-man spot. It’s possible that they find a Swihart trade between now and when Pearce is officially placed on the roster (I’m assuming they’ll try to make this happen for Friday’s game, but as far as I know that hasn’t been guaranteed as of this writing), but Lin would be the casualty on which I’d bet.

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So, if we assume that is the move, the position player side of the roster is as follows. (Starters and bench players are obviously not set in stone.)

C: Christian Vazquez

1B: Mitch Moreland

2B: Eduardo Núñez

3B: Rafael Devers

SS: Xander Bogaerts

LF: Andrew Benintendi

CF: Jackie Bradley Jr.

RF: Mookie Betts

DH: J.D. Martinez

BN: Sandy León

BN: Brock Holt

BN: Blake Swihart

BN: Steve Pearce

Okay, so the roster is set. Now, it becomes a question of Pearce’s role. The obvious role, and essentially the whole reason they traded for the righty, is to hit left-handed pitching. We all know about the team’s struggles against southpaws this season, and while they’ve looked better of late they still have a season slash-line .257/.318/.413 for a 97 wRC+. Pearce, meanwhile, has a 143 wRC+ against lefties this season and a 127 mark over his career. He is clearly an improvement and a boon for the team in this regard. They just need to figure out how to get him into the lineup when a lefty is on the mound.

Defensively, Pearce has played first base, both corner outfield spots and even third and second base. Those last two positions are in the past, however, and we certainly shouldn’t expect the 35-year-old to play either spot in 2018. This season, he has ten games at DH, nine games in left field, three games at first base and two games in right field. Pearce is not a good defensive outfielder, and while he could likely make it work in smaller fields like left field at Fenway, presumably Martinez is ahead of him on the outfield depth chart.

Instead, I would assume he will see most of his time at first base and DH with some sparing moments in the outfield. The most obvious role for Pearce would be as a platoon partner with Mitch Moreland. This was, in an ideal world, the role Hanley Ramirez would have filled if he was still with the team. However, Moreland has actually been good against lefties this year with a 122 wRC+. That is boosted by an unsustainable .395 batting average on balls in play, but he also has an impressive .202 Isolated Power against southpaws.

Checking in on the Red Sox halfway through the year

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All of that is to say that I can’t imagine they’ll always sit Moreland against lefties. Pearce will get some time at first in these situations, but it’s also likely he’ll slide into the DH spot on these days. In fact, it wouldn’t be terribly surprising if Bradley Jr. was affected more by this move, with Benintendi sliding into center field, Martinez into left and Pearce at DH. The defense would be downgraded in this scenario, but the offense would certainly get a big boost, even given how much better Bradley has looked of late. Ultimately, it’ll probably be a split between these two scenarios.

So, Pearce is going to start pretty much every game against left-handed pitchers, but that won’t be his only role. The 12-year veteran also gives the Red Sox their best pinch hitting option they’ve had since Ramirez’ release. When opponents bring in a left-handed reliever late in games — think Aroldis Chapman and Andrew Miller, among others — Pearce will be a big asset off the bench. It should be mentioned that he does not have a great history in this role, hitting just .193/.279/.294 in 122 plate appearances as a pinch hitter. That certainly wouldn’t stop me from using him in this role, but it’s worth keeping in mind. Pinch hitting is more difficult than many give it credit for.

We knew at the time of the deal that Pearce was far from a blockbuster acquisition, but it’s clear that he has the potential to play an important role for the Red Sox. Hitting left-handed pitching has been a weakness for this team all year, and now they have one of the more unheralded platoon bats in the game. He’s probably going to shift between first base and DH and won’t provide much in the way of defensive value, but as long as Pearce mashes lefties in the way that he’s capable this will be a good move for the Red Sox.