Jayson Werth. (AP Photo/Alex Brandon)

Jayson Werth did not start in two straight games with nagging shoulder and ankle injuries, but on Sunday the Nationals’ outfielder said it was, in fact, his right shoulder that has been bugging him the most. Werth said he has inflammation in the AC joint of his right shoulder, and the pain was so bad a few days ago he couldn’t lift his arm up to his head. He can now.

Werth is back in the Nationals’ lineup on Sunday night and, barring any setbacks pregame, he was slated to start in right field. After resting and receiving treatment, Werth felt well enough to play. But the sore shoulder will still require care.

“This is the first for me,” Werth said. “It first was bothering me when I was swinging. Just progressively got worse and worse every day. It was that Thursday we played that long game and by the end of that game it was bothering me throwing. Then the next day it was pretty blown up. I think it’s just an inflammation thing and you try and get that under control. It should be playable.”

Werth said the injury first likely occurred on Aug. 1 against the Phillies in Washington. He made a diving catch, threw out a runner at home and made a jumping catch at the wall. When he reached for the ball at the wall, his glove was up over his head and the exposed shoulder hit the wall.

“It didn’t look like much on the replay,” Werth said. “But just having my shoulder up above my head and it hit the wall just kinda right.”

Werth said the ankle he sprained on July 28 hasn’t been much of a problem. He received Friday off to take care of his nagging injuries and he was in Saturday’s original lineup before being scratched. He pinch-hit in the 11th inning and drew a walk but was lifted for a pinch runner.

“I probably wasn’t, I guess, healthy enough [to start],” he said. “You just don’t want to risk [it]. It’s tough because you want to play, but it’s the type of injury that is painful and they tell me I’m not at risk of injuring myself I guess once it’s to a level that’s tolerable. … It’s tricky.”

Werth played with the sore shoulder for a few days and it didn’t truly become an issue until a 13-inning game on Thursday.

“A couple swings kinda [aggravated it] to the point where it was inflamed and sore,” he said. “And that’s where we’ve been the last couple days. Hopefully with the day off [Monday], a couple days off there, I don’t know. I’m somewhere where I’ve never been before. I think I’m going to be okay.”

Nationals Manager Matt Williams said he hoped the two days of rest and Monday’s off day will calm Werth’s shoulder inflammation.

“Inflammation, if you don’t play, it calms down,” Williams said. “The problem is, if you do it again, it just comes back. He gets it a little more when he takes a funky swing, if he gets fooled on a breaking ball or has to reach for a ball out there.”