Despite concern after ACL tear, Eaton should be upgrade for Nats

We've spent a decent portion of the offseason to date talking about members of the 2017 Nationals who won't be part of the 2018 Nationals, but we'd be remiss if we didn't take some time to talk about a guy who barely played in 2017 who is positioned to play a whole lot in 2018: Adam Eaton.

The club's biggest acquisition last winter, Eaton was going to be in the crosshairs throughout the season, with fans, media members and even those on the roster curious to know whether the scrappy outfielder was worth the hefty price Mike Rizzo sent to the White Sox to get him (three pitching prospects, including Lucas Giolito and Reynaldo López).

We only got a month's worth of playing time to make an evaluation, but Eaton sure did look worth it during that dynamic April. In 23 games, he hit .297 with a robust .393 on-base percentage, an .854 OPS and 24 runs scored. FanGraphs assigned him a WAR of 0.5, a value that would've been greater if not for a negative defensive rating in center field.

In short, Eaton was everything the Nationals touted him to be: a top-of-the-order offensive player who had the ability to get on base, to get around the bases and drive others in if the situation presented itself. The 28-year-old quickly won over fans with his hustle and never-let-up style of play.

That relentless approach to the game, of course, may have led to the injury that brought an abrupt end to his first season in Washington on April 28. Trying to beat out a grounder to short in the ninth inning with his team down two runs, Eaton's left foot landed awkwardly on the front of the first base. He fell to the ground in a heap, the ACL in his knee having fully torn, with damage also done to his meniscus and ankle.

Just like that, Eaton was done for 2017. The Nationals had little trouble making up for his absence, thanks in large part to the long-awaited emergence of Michael A. Taylor. But it was fair to wonder if Eaton might have made a difference come October, where his ability to grind out at-bats and put the ball in play might have been magnified.

We may just learn the answer in 2018, assuming Eaton makes a full return and picks up where he left off when he got hurt. Though, it should be noted, that's hardly a guarantee.

ACL injuries aren't as common in baseball as they are in football and basketball, and the track record for players returning 100 percent healthy is strong. According to a study of major leaguers who suffered torn ACLs from 1999-2012, 88 percent returned to play at least 30 major league games (the highest rate of return in professional sports). But that doesn't necessarily mean their performance returned to the same level.

According to that study, those players whose ACL tear was to their rear hitting leg saw their batting average decline an average of 12.3 percent. Strangely enough, those who tore the ACL in their front hitting leg actually saw their batting go up an average of 6.4 percent (perhaps because while rehabbing they did extra work on their healthy leg).

None of that means Eaton is destined to become a worse hitter when he returns, but it's something to consider. The good news: Players returning from ACL tears showed no ill effect on their stolen base totals.

So we'll have to wait and see how exactly Eaton looks and performs once he takes the field in the spring. But even if he's something less than his pre-injury self, he should still be a welcome addition, both in the lineup and especially in the field.

Eaton may have posted poor defensive numbers in center field, but he'll be ticketed to play left field in 2018. That was the Nationals' intention all along, recognizing that he's a better corner outfielder and that one of the spots would open up next season once Jayson Werth's contract expired (with the possibility of right field also opening up in 2019 if Bryce Harper departs).

Eaton last played a corner position in 2016 with the White Sox, during which time he posted a Defensive Runs Saved rating of 22, among the best in baseball. The upgrade he provides from Werth will be substantial.

Rizzo made the controversial trade to acquired Eaton last winter not only for short-term help but for long-term stability. Eaton is under team control for another four seasons for a modest $35.4 million.

His first season in D.C. may have fallen apart on that fateful night in April, but the Nationals still expect to reap the benefits of his presence for several seasons to come.