(Evan Vucci / AP)

The Nationals officially placed Ross Detwiler on the disabled list today, making him the fourth National to land on the DL in the last 11 days. That does not include Danny Espinosa and Bryce Harper, who are out of today’s lineup with a bone chip in his right wrist and bursitis in his left knee, respectively. “We’ve got a regular MASH unit,” Manager Davey Johnson said.

This morning, Nationals team physician Dr. Wiemi Douoguih provided updates on the Nationals’ walking wounded. Aside from Harper, the big picture is this: Espinosa could return this week; Wilson Ramos will miss at least another month or so; and Jayson Werth’s strained hamstring remains a source of confusion.

Espinosa, who discovered Friday he had played for a month with a piece of bone chipped off his right wrist, took batting practice today after resting for several days. The Nationals were optimistic about his session, and depending how the wrist responds later today Espinosa may be back in the lineup by the middle of the week.

“It looked good today, swinging,” Douoguih said. “He said it felt better. We’re just going to ramp him up over the next couple days, and hopefully he’ll be ready to go.”

The Nationals expected Espinosa will have to play through pain. If swelling returns to his wrist after today’s hitting, he will likely be placed on the disabled list, although Douoguih said surgery is not an option.

“We’ve already tried a couple times to rest it and get him back,” Douoguih said. “If it flares up again, we’re going to have to have a more extended period of rest.

“This is not like a surgical issue. This is something that needs rest. How much rest really depends on his body, how his body responds to the different stresses we put him through. If he’s able to go, he’s able to go. It’s something that might be sore for him for a while. We’re hoping that it clears up and it just doesn’t bother him.”

Douoguih also clarified the timeline of Espinosa’s injury. On April 14, Braves lefty Paul Maholm hit Espinosa in the wrist with an 88-mph fastball. An X-ray showed no structural damage where the pitch hit Espinosa. But it did reveal an apparently unrelated bone chip.

“He did have some findings on the initial X-ray, but it was away from where he was sore,” Douoguih said. “We thought that it might be old, it wasn’t bothering him. A couple weeks ago, he developed new pain in a new location that was around where the bone chips were. That’s where we became more concerned.

“The bone chip that he has is almost like a bruise. It’s not a fracture as we would normally think of a broken bone. It’s something that tells us there’s something wrong there, but structurally, everything else is sound in that area, in his wrist.”

The Nationals have even less clarity when it comes to Werth’s status. Werth, who has not played since May 2, could appear in minor league rehab games as soon as this week and may return to the Nationals early next week. He did some running yesterday, and “looked good,” Douoguih said.

From the start, Werth’s injury has confounded the Nationals’ training staff. At the time he strained his hamstring, he also dealt with stomach issues that left him dehydrated. The Nationals have had difficulty determining the severity of the strain and how much of the problem relates to his dehydration.

“It’s been a challenge, because when he developed this hamstring problem, he also had this problem with the bowel issue and dehydration,” Douoguih said. “So he had a lot of cramping. It was hard to tell whether some of it was induced by the cramping of the dehydration, or whether it was strictly a hamstring issue. He is getting better. We anticipate he’ll be on track getting back sometime next week. We can’t tell. We just have to take it one day at a time.”

The Nationals have a better of idea of Ramos’s table, but it’s not very heartening. Ramos re-aggravated his left hamstring on May 15. Douoguih said he will miss about six weeks from the day of the injury. Ramos already missed 15 days because of a hamstring strain he suffered earlier in the season.

“When he came back, he was pain-free,” Douoguih said. “He went through a slate of hamstring rehabilitation and met all of his milestones. We felt he was ready. Whenever there’s a setback like that, you tend to be more concerned and give it more time.”