The Washington Nationals are off to an impressive 16-8 start -- the best record in the National League. Yet the mood in D.C. is about to grow somber.

That's because center fielder and big winter acquisition Adam Eaton is reportedly done for the season with a torn ACL, per Ken Rosenthal:

Eaton left Friday's game, collapsing after legging out an infield single. He had to be carted off the field.

If Eaton is indeed out for the year, it's a big blow for the Nationals, who surrendered multiple top prospects to acquire him during the winter. Eaton had thus far proved worth the investment. He entered Saturday batting .297 with a 128 OPS+. 

In Eaton's place, the Nationals are likely to turn to former top prospect Michael Taylor. Now 26 years old, Taylor has heretofore failed to establish himself as a legitimate big-league hitter. In fact, he has a career 70 OPS+ in more than 800 plate appearances. The biggest problem for him has been strikeouts -- he's fanned in nearly a third of his trips to the plate.

The Nationals could look outside the organization, but the trade market offers slim pickings, and the top free-agent outfielder (Angel Pagan) has said he's sitting out the season. Top prospect Victor Robles, meanwhile, has yet to play in a Double-A game.