(Joe Robbins/GETTY IMAGES)

“Losing Willy is a big, big blow,” Johnson said. “I don’t know how bad it is. I have bad feeling he tore something in there and it’s going to be a while. Just keep our fingers crossed. But right now, it’s not good at all.”

In the seventh inning of the Nationals’ 2-1 victory over the Reds, Zimmermann fired a high, 93-mph fastball beyond the right edge of the plate. Ramos lunged for the ball, which deflected off his glove and trickled behind him.

As he scooped the ball, his spike caught in the grass and his knee buckled, bending unnaturally sideways. Ramos crumpled to the ground and lay on his stomach, his face in the grass, until Nationals trainers arrived. Ramos came off the field with both arms around a Nationals trainer, no weight on his right leg.

Without Ramos, Flores would become the starter. The Nationals will likely call-up Carlos Maldonado from Class AAA Syracuse to be his backup. The Nationals’ other options would be Jhonatan Solano, who just returned from an injury at Syracuse, or Sandy Leon from Class AA Harrisburg. The Nationals believe Leon, 23, can catch and throw at a major league level.

Flores, 27, became Washington everyday catcher in 2009, but a torn labrum in his shoulder sidelined for nearly two years until he returned last season.

“It is sad,” Flores said. “I’ve been there. I know he doesn’t feel very good. I hope it’s nothing serious and he’ll be fine. I went and talked to him, and he said he doesn’t feel well.”

Ramos’s apparently serious injury adds to their long list of key injuries. The Nationals have played all season without projected cleanup hitter Michael Morse and closer Drew Storen. Ryan Zimmerman, Jayson Werth, Rick Ankiel, Mark DeRosa, Chien-Ming Wang and Brad Lidge have all spent time on the disabled list. The Nationals also played four games without first baseman Adam LaRoche.

“We’ve got pretty good depth here. We’ve got a lot of talent here,” Johnson said. “But I think we’ve had enough.”

For more on Ramos’s injury, teammates’ reaction and the Nationals’ 2-1 victory over the Reds, go here.