WASHINGTON -- The Washington Nationals lost more than a game Friday.

Sure, falling 7-5 to the division-rival New York Mets hurts. Yeah, it stings to load the bases with nobody out in the bottom of the ninth only to watch Trea Turner whiff and Bryce Harper ground into a game-ending double play. But that’s small potatoes. The papas grandes? That would be the loss of Adam Eaton.

With runners on first and third and nobody out in the ninth, Eaton stepped in against Mets closer Jeurys Familia and slapped a slow roller to the left side of the infield. Shortstop Asdrubal Cabrera ranged toward third base, backhanded the ball and made a hurried toss to first. The speedy Eaton just barely beat the throw, but when he planted his left foot on the bag on a stretched-out last step, he melted to the ground as if he was the Wicked Witch of the West in a rainstorm, tumbling head over heels before coming to a stop about 10 feet past the base. To the naked eye, it was hard to tell exactly what happened. Upon further review, replays showed Eaton’s ankle turning in a manner that ankles aren’t accustomed to turning.

Just like that, the crowd of 34,000-plus at Nationals Park, which had been in full voice only a moment earlier, fell silent. The silence continued as Eaton lay on the ground for several minutes while being examined by Washington trainer Paul Lessard. It continued as Eaton had to be carried off the field, each arm around a helping shoulder with both feet dangling above the ground. It continued after the game, in the home clubhouse.

"It's just awful,” said an unusually somber Max Scherzer. “Especially when you see the replay, he comes up short of the bag, and you see his ankle roll over, his whole leg kind of falls apart. Seeing him in the training room, it's an awful feeling. You hate seeing your teammates, those guys injured severely. And I think that's what happened.”

Said Harper: “I don’t know what happened to him, if it got his knee or his ankle or his whole leg. But it’s just a scary situation, and you hope he’s OK. I guess we’ll see later on.”

Later on is Saturday, when Eaton is scheduled to undergo an MRI, according to manager Dusty Baker. In the meantime, baseball fans in D.C. are holding their breath, a reaction that nobody could’ve foreseen back in December. That’s when Eaton came to the District, the centerpiece of a blockbuster deal in which Washington gave up three stud pitching prospects, including heralded hurler Lucas Giolito. At the time, the trade was panned. The consensus was that for once, general manager Mike Rizzo, known for his shrewd trades, had come out on the short end -- that the cost to acquire Eaton, a good but not great player who’s never been an All-Star, easily outweighed the benefit.

“When we traded those guys for him,” first baseman Ryan Zimmerman said, “everyone freaked out.”

Nearly five months later, everyone’s still freaking out over Eaton. Only now, it’s for a different reason. Entering Friday, he was hitting .291 with a .392 on-base percentage that was second-best among Washington players and ranked 15th in the National League. His 24 runs scored were second-best in the NL, and he’d reached base safely in 19 of 22 games. Perhaps even more importantly, he helped the Nats withstand the loss of Turner, moving from the 2-hole into the leadoff spot after Turner hit the disabled list with a tweaked hammy. When Turner came off the DL last week, Eaton remained at the top of the lineup, a clear sign of just how valuable he’s been to a Washington offense that’s leading the majors in average (.287), OPS (.847), and scoring (6.3 runs per game). Even though the Nationals’ lineup features thumpers such as Harper, Daniel Murphy and a revitalized Zimmerman, it’s Eaton who’s been the igniter.

“He came over and did everything expected and more,” said Zimmerman, who hit two more homers Friday to give him 10 on the season. “That’s hard to do when you get traded for guys like that and everyone puts a lot of pressure on you. But he just came in, and he plays the game hard, plays the game the right way. He’ll be back for sure.”

Exactly when Washington’s center fielder will be back remains to be seen. In his absence, manager Dusty Baker has options, but none of them are ideal. Michael Taylor is a solid defender who struggles at the dish, hitting just .095 in limited action. Veteran Chris Heisey is more dependable at the plate but is more of a corner outfielder. Turner, a natural shortstop, converted to center field last season as a rookie and could theoretically go back out there, but that would leave a major hole in the infield, especially with utility man Stephen Drew (hamstring) on the disabled list. In other words, the Nats are going to miss Eaton.

Only time will tell how long.