(Kathy Willens/AP)

“I’m 100 percent fine,” Espinosa said. “There’s nothing wrong.”

Last year, Espinosa played in every game from opening day through Sept. 2, his first day off. This season, his first off day comes five days into the season. “It surprised me,” Espinosa said. “I thought I’d be playing.”

Espinosa was momentarily dazed Mondayin the ninth inning. While covering first on a bunt, Ruben Tejada collided with Espinosa and knocked Espinosa’s head with his elbow. Espinosa chased down the ball, having lost his glove in the collision, and fired it across the field to third baseman Ryan Zimmerman.

A couple Nationals coaches today mentioned what an impressive throw that was. First, it was a bullet from the strong-armed Espinosa. Second, he made it without his glove, which is much trickier than it sounds or looks. Third, he had just been nailed in the head.

After the play, Espinosa knelt down with his hands on his knees, trying to gather himself.

“I got hit. I panicked because I knew the ball had gotten away,” Espinosa said. “I just kind of rushed. I just need a couple seconds just to kind of regroup. Probably just a lot of adrenaline.”

Immediately afterward, Nationals doctors administered concussion tests on Espinosa. They had him balance with his feet in a line with his eyes closed. They asked him if he felt nauseous. He passed without issue.

Espinosa still felt no nausea this morning and went about his typical daily routine. Until he arrived at the park, when he found his name off the lineup card.

“I don’t want him out there with a stiff neck or being woozy,” Johnson said. “I’m just going to be cautious. With everything else going on, him I said, ‘Sit over here with me.’ ”