The fates of Bryce Harper and Adam Eaton are likely intertwined. (Katherine Frey/The Washington Post)

When the Washington Nationals traded for Adam Eaton two winters ago, the best justification for the deal seemed to linger somewhere in the future — more specifically, a Bryce Harper-free future. By trading for Eaton, logic held, the Nationals had ensured at least one-third of their outfield would be in place long-term. They locked up a reliable leadoff man with plenty of grit, the kind of player as useful in an outfield with Harper as he was without him — a steady force should that outfield fall into the hands of young prospects instead.

But now, as Harper’s decision looms and leaves the Nationals outfield in purgatory, Eaton’s role seems somewhat less clear. If Harper signs, he will almost certainly play alongside Juan Soto and Victor Robles, two prospects no one in the Nationals' decision-making corps would allow to sit idle for Eaton. If that happens, what happens to Eaton?

To be clear, far more scenarios exist in which the Nationals very much need Eaton’s services than can find them disposable. If Harper doesn’t re-sign, an outfield of Soto, Robles and Eaton becomes one of the more athletic, exciting and high-energy groups this team has ever compiled out there. Should Michael A. Taylor remain as a fourth outfielder, the Nationals will surrender some power production in Harper’s absence, but greatly increase their speed and collective defensive abilities. General Manager Mike Rizzo and Manager Dave Martinez have said over and over that they would like a more athletic roster. One can see why that outfield group would appeal to them.

Eaton has hit .300 with a .394 on-base percentage with the Nationals. His everyday peskiness, when healthy, at the top of the order would be a settling and encouraging influence. Only eight players in baseball had an on-base percentage higher than .394 this year: Mike Trout, Mookie Betts, Joey Votto, Brandon Nimmo, Christian Yelich, J.D. Martinez, Lorenzo Cain and Alex Bregman. Harper owned an on-base percentage of .393.

Even if Harper stays, the Nationals could find themselves needing Eaton. Should Harper stay, and the team commit the tens of millions of dollars required to make that happen, they will have to reboot this roster largely via the trade market. As they do not want to eclipse the competitive balance tax threshold again, they will not want to commit major money to multiple free agents beyond Harper. Upgrades to their starting staff, behind the plate, and at second base might come at a better price via trade — though if their targets include Marlins catcher J.T. Realmuto and/or a front-line starter, Robles and others would almost certainly be an asking price.

The Nationals have deemed Robles almost untouchable to this point, and no one has indicated that stance has changed. The adjustments he made in late September suggest he is not only big league ready, but capable of struggling and emerging — a major prospect hurdle. But should they trade him (a Soto deal seems even more unlikely), they have room in their outfield for Eaton. Once again, either Harper or Eaton would have to play center to get them both in the starting lineup. Harper rated as one of the worst defenders there this season, and the Nationals still believed he could move better than Eaton. A late-inning replacement such as Taylor can only help so much. An outfield of Soto, Harper and Eaton — like the one that played much of the second half — would be far clunkier than their other options.

In the event that the Nationals re-sign Harper and do not trade one of their young outfielders, Eaton might have more value as a trade chip. If Robles is on the roster, he will almost certainly start in center field. Soto is not moving. Harper will play right. In that case, though Eaton’s salary is not a burden, he probably won’t provide the kind of production in a limited role he could bring via trade. Certainly, his return would not compare to that of Robles.

Yet, as those on-base percentage numbers demonstrate, he is an underrated offensive performer on a team-friendly contract. Eaton is due $8.4 million in 2019 and $9.5 million in 2020 with an option for 2021. The Nationals could not expect to get the kind of return they paid for Eaton two winters ago, when they surrendered three top pitching prospects — Lucas Giolito, Reynaldo Lopez and Dane Dunning — to the Chicago White Sox. But they would get something substantial.

Trading Eaton would, however, remove one of the few players in that clubhouse with the hard-nosed, gut-it-out mentality this team seems to need. It would remove an everyday player with the kind of fire Rizzo has hunted for years. And it would remove one of the best leadoff men in baseball from a team that has seen the importance that role can carry. As much as Trea Turner has improved in recent years, as much promise as Robles has near the top of the order, neither has the strike zone knowledge nor on-base capabilities of Eaton.

Eaton’s fate, like so many others, remains directly tied to Harper’s. The pesky leadoff man could become a staple of this Nationals outfield for years to come — unless they decide they have too many such staples, in which case, he could be gone.

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correction: An earlier version of this story mistakenly identified Eaton's buyout salary for 2020 ($1.5 million) as his salary. He will make $9.5 million in 2020.