(Evan Vucci / AP)

The Nationals entered the season with a clear-cut plan at second base. The position belonged to Danny Espinosa, the homegrown, high-ceiling slugger who had held the spot the previous two years. He had slumped often in 2012, and he was playing with a tear in his left rotator cuff, but the Nationals were unflinching: Espinosa was their second baseman.

“There’s a reason he’s out there,” General Manager Mike Rizzo said. “He’s our best option that we have, and he’s the guy we want out there, or else we would have done something with that position in the offseason. He’s the guy we’re counting on.”

Espinosa has floundered through the first quarter of the season, regressing rather than taking a step forward.  He entered Sunday hitting .168 with a .197 on-base percentage and a .305 slugging percentage, which gives him the lowest on-base percentage in the National League and the fifth-lowest OPS among major league regulars. He has 37 strikeouts, three walks and 12 extra-base hits.

The start, though, has not changed Rizzo’s opinion. He said he plans to stick with Espinosa, and sending him to the minors to regroup is not an option he has considered.

“I don’t think so,” Rizzo said. “He’s physically fine. He’s mentally fine. He’s got to get his fundamentals and mechanics down. He’s got to make some adjustments. We’re hoping those come sooner rather than later, because he brings a lot to the table as a player.

“I will say, the good thing he hasn’t taken his offense on the defensive side. That’s a testament to his mental toughness. But like we’ve said, it’s a performance league, and you have to perform.”

The Nationals have options. Steve Lombardozzi has filled in at second base before, although he entered Sunday hitting .210. At Class AAA Syracuse, Jeff Kobernus, a speedy, athletic utility man with significant experience at second base, is hitting .348 and nearly made the Detroit Tigers this spring as a Rule 5 pick. Anthony Rendon, the Nationals’ best prospect, has played second base twice since the Nationals sent him back to Class AA Harrisburg, and he has pounded the ball.

Still, Rizzo believes Espinosa at second gives the Nationals their best chance to win. And in one regard, he is right. Because of Espinosa’s elite defensive skill and the power threat he provides, the Nationals’ highest ceiling includes Espinosa playing second. He just needs to perform.

“He’s our long-term solution at second base,” Rizzo said. “Hopefully, he comes out of this funk of his and comes back to his career norms. Or, I was thinking, a tick better than his career norms this year and taking a step forward in his progression.”