Richard Lipski /AP

In a Nationals season uninterrupted by injury, Danny Espinosa has been the exception. “My little iron man at second,” Manager Davey Johnson said. He has played in 144 of 146 games, through slumps and nagging injuries. But as the Nationals near the postseason, his status is suddenly in jeopardy.

Espinosa will receive an MRI exam on Monday afternoon on his left shoulder, which has bothered him for the past week, Johnson said. He will miss at least the Nationals’ upcoming three-game series with the Dodgers.

As the Braves swept the Nationals this weekend, Espinosa went 0 for 11 with nine strikeouts and a double play, clearly affected by the injury. Johnson pinch-hit for him with two outs in the ninth in Sunday night’s 5-1 loss, a rare but necessary measure.

“He never wants to come out of the game,” Johnson said. “I wasn’t going to hit left-handed, and he said it’s even bothering him right-handed. So I’m pretty concerned about him.”

Espinosa could miss more time than just the Nationals’ next three games. Johnson said Espinosa has been talking to Adam LaRoche to see if his injury bears any resemblance to the torn labrum LaRoche suffered last season. LaRoche underwent season-ending surgery that cost him the year’s final 117 games.

The weakness in Espinosa’s shoulder explained his sudden slump – Espinosa had hit .300/.364/.500 in his previous 36 games, before he left the team for Wednesday’s game to attend his grandmother’s funeral. Sunday night, Espinosa alerted hitting coach Rick Eckstein that he couldn’t perform.

“He was underwater,” Johnson said. “He was hurting the team.”

Espinosa recovered from a first-half rut to become a key cog in the Nationals offense during the second half. Since the all-star break, Espinosa has hit .275/.327.454 with nine home runs. At second base, he could be a Gold Glove candidate.

“Any time one of your everyday guys that’s been a big part of this team, hopefully it’ll just be something little,” third baseman Ryan Zimmerman said. “Hopefully it’ll be nothing and he’ll be ready to go.”