WASHINGTON -- The Nationals made a plethora of roster moves on a busy morning prior to Wednesday's series finale against the Braves.
They placed left fielder Adam Eaton on the disabled list with a bone bruise in his left ankle and activated catcher Matt Wieters from the DL, both moves as expected. But they also called up outfielder Moises Sierra and to clear room on the 40-man roster, designated catcher Miguel Montero for assignment.
It will leave the Nationals without Eaton, who had been one of their hottest hitters at the leadoff spot to set the table for the rest of their lineup. In eight games, he started the season batting .345/.424/.655 with 10 runs scored. But after the left ankle tweak Eaton suffered last week lingered enough for him to get scratched from the lineup Tuesday night, the Nationals decided to treat Eaton carefully considering he is still working his way back from a torn ACL.

"We're going to be very, very cautious," manager Dave Martinez said. "One, it's the ankle that he hurt last year. And we don't want any setbacks on his knee. So it's a bone bruise, but it's a bad bone bruise and it bothers him. So we thought, rather let him miss 10 days than it become 3-4 weeks."
With Eaton on the DL, the Nationals wanted to carry another outfielder on the roster and a right-handed bat off the bench. So they turned to Sierra, who impressed the club during Spring Training when he hit .321 (17-for-53) with a pair of home runs and 11 RBIs in 30 games. Sierra does have some Major League experience with the Blue Jays and White Sox, although he has not played in the Majors since 2014.
"The biggest thing I think is I've gained a lot of experience," Sierra said through an interpreter. "And this is what I feel like I can bring to the team now, is the experience I've developed. It's helped me grow as a player and I feel like that's going to help me perform a lot better up here now."

In order to clear room for Sierra, the Nationals decided to part ways with Montero, who made the club after entering Spring Training as a non-roster invitee. It was an abrupt end for Montero, who just returned from the paternity list Tuesday afternoon, and played in just four games this season, where he went 0-for-11 with two walks.
"The hardest thing for me is letting guys go like that," Martinez said. "I've known Miggy a long time personally, know his family, but it was tough. He gets it. He wanted me to thank everybody, which I will. We gave him an opportunity, it just didn't pan out."
The move for Montero was made easier because of what the team saw from Pedro Severino, the club's No. 20 prospect as rated by MLB Pipeline, since he was promoted to the Majors this year. In seven games, he is batting .368/.520/.474 which has earned him a chance to stick in the Majors.
The team had discussed carrying three catchers for a bit, but ultimately decided it wanted to just focus on splitting the playing time between Wieters and Severino. It is unclear how exactly the Nationals plan to split playing time between them, Severino will continue to get opportunities to earn playing time, especially because Wieters just returned from a mild oblique strain.
"Sevy's earned the right to play," Martinez said. "I want him to play. He's done well. We'll see what we can do and see how we can match them both up."
Murphy could head to extended spring next week
If Daniel Murphy continues to make progress consistently, he could be headed to extended Spring Training next week to continue rehab from microfracture knee surgery. That would line up for Murphy to go to the team's complex in West Palm Beach while the Nationals begin a 10-day road trip. Martinez said earlier in the week that the last step for Murphy would be to start running the bases aggressively.

"He does a lot in the training room before he even goes out there to get ground balls," Martinez said. "He's doing well ... hopefully we'll know by this weekend, but he's doing great."