[Updated: 6:34 p.m.]
With Nate McLouth battling right shoulder inflammation, the Nationals placed the veteran outfielder on the 15-day disabled list Monday and called up Triple-A standout Steven Souza, Jr. as the corresponding move.
McLouth's disabled list stint is retroactive to Aug. 2. The 32-year-old has struggled this season with a .179 average and .517 OPS through 79 games.
McLouth received an MRI and a cortisone shot on Monday, manager Matt Williams said. The skipper categorized the injury as "nothing serious."
"He's fine," Williams said. "He's got some shoulder inflammation. He saw the doc and had an MRI today and a shot to calm it down. It's just inflamed. We decided to go ahead and put him on the DL to get him right."
The Nationals believe McLouth sustained the injury while diving for a ball against the Miami Marlins on July 28. General manager Mike Rizzo expects to see the outfielder return before rosters expand in September, but does not know how long he will be out.
"The shot takes you out about five days. After five days we'll know more. He can't do anything baseball related for five days. Then after that we should start gradually progressing him to being ready to play. He'll go out and play a few rehab games and then we'll see him back."
Souza joins the Nats for the second time this season. He came up to make his MLB debut on April 13 and went back to Syracuse after going 1-for-8 with three strikeouts and a walk in eight major league games.
Souza has since become a star in the minors, leading the International League with a .354 batting average and a 1.036 OPS. In 91 games with Syracuse this year, he has 18 home runs, 23 doubles and 24 stolen bases.
"It’s definitely exciting because these guys are in first place and hunting a World Series," Souza said. "Any way that I can help this team win a World Series that’s what I’m here for. Whatever role they put me in, I’m ready to accept the challenge."
Souza, 25, will join the Nationals bench likely as their fifth outfielder, but he did take groundballs at first base before Monday's game. Williams would not rule out playing him at first some day, however, he denied it will happen any time soon.
"Don't make too much of that, that's just part of his routine," Williams said. "He does that on a regular basis, even when he's down in Syracuse. He started that in spring training. He just takes groundballs there. He will be hopefully in games.
"We have a limited number of off-days before the first of September and even beyond that. A lot of our guys have played a lot of games, so we have to look at potential days where we can get them off. Jayson is one of them, Denard's one of them. So I would anticipate Steven will be in the lineup from time to time starting, certainly coming off the bench to pinch-hit and running the bases. He adds a lot of things to our club."
Rizzo also said he considers Souza - who was drafted as a shortstop and played first base for most of 2011 - as an outfielder.
"I think that we see him as an outfielder, probably a corner outfielder in the future if I were to have to put a position down right now," he said.
"We've bounced him around with a plan in mind that we want him to get familiar and comfortable at all three positions. That gives us a lot of flexibility in the future."