Nationals' ace starter Gore placed on 15-day injured list due to left shoulder inflammation, aiming to return by season's end.

Washington Nationals' All-Star lefty MacKenzie Gore was added to the 15-day injured list today due to left shoulder inflammation, retroactive to Thursday, yet he stays hopeful about returning to the mound this season.

“It’s a sensation, and from my last start, we decided I need an MRI,” said 26-year-old Gore at Nationals Park before today’s 1-4 defeat to the Rays. “There’s nothing seriously wrong. I didn’t want to go on the injured list, but it was somewhat necessary. I plan to come back as soon as possible; we just need to clear some things up inside, and it should be fine.”

Gore last pitched on Wednesday against the Yankees, throwing five innings in New York, giving up three runs on three hits, and narrowly escaping a tough third inning after 38 pitches. After an impressive first half and his first All-Star selection, Gore posted a 7.54 ERA with a 1.76 WHIP over eight starts in the second half.

“I think you always feel some discomfort, especially entering September,” Gore said. “Our recovery methods weren’t right, so we had to check it out. We made a good call by catching the issue early.”

As part of the roster move, the Nationals recalled right-handed reliever Mason Thompson from Triple-A today. Acting manager Miguel Cairo said the Nationals plan to bring up another pitcher from Rochester when rosters expand in September to fill Gore’s spot in the starting rotation.

“He’s a player who wants to compete,” Cairo said. “We just want to make sure he’s healthy enough. If he can pitch again this year, that would be fantastic. We’ll take it step by step, see how he feels, how he recovers, and how he handles things in the training room, making sure his shoulder returns to normal.”

Gore, the Nationals’ Opening Day starter, has appeared 27 times in his fourth Major League season, accumulating 147.1 innings pitched. Last year, he set a career high with 166.1 innings across 32 starts.

“I have to be honest with myself,” Gore said. “My body wasn’t at the level it needed to be. Sometimes, when you pitch injured, if you really push through, you risk seriously hurting yourself.”

With a month left in the regular season, Gore sees plenty of time on the calendar to prepare for his comeback.

“We have to rebuild some strength and get everything running the right way,” Gore said. “That’s what we’ll be working on over the next 15 days, and I plan to be ready.”