"He looks good. He's throwing the ball well," St. Claire said.
Armas will accompany the team to Washington for the home opener on April 14 and then have a rehab assignment to get his pitch count up shortly thereafter.
Once Armas is ready to pitch in a big league game, one of the pitchers will have to be sent down. Manager Frank Robinson indicated on Sunday that he would mostly likely go with 11 pitchers instead carrying an extra hurler.
Armas' return also would mean that John Patterson would return to the bullpen.
Injury report: Outfielder Ryan Church played left field for the second consecutive day on Sunday against the Marlins. Robinson will be playing Church at the corner position until the tightness in his groin is completely healed. Church is expected to be the everyday center fielder with Brad Wilkerson playing left.
Nothing is permanent: On Sunday, Robinson said that Nick Johnson will not be batting second all season. Once Cristian Guzman gets out of his hitting slump, Robinson wants the switch-hitter to be hitting behind Wilkerson, the leadoff hitter.
While Johnson can work the count and draw more walks, Robinson feels that Guzman has better bat control and will not strike out as often.
"Sometimes you make [Guzman] give himself up by hitting the ball behind the runner. You can bunt with him a lot," Robinson said. "I feel I can't do that with Nick and put him in that type of hole. Nick has done a good job batting second, but he's not the ideal second-place hitter."
Stat of the day: Entering Sunday's action, the Nationals' bullpen leads the Major Leagues in victories with three.
Did you know? Church has hit two career home runs and both of them have been hit against the Marlins. Church's first home run came last September against right-hander Carl Pavano, and his second one was hit on Saturday against right-hander Brian Moehler.
On deck: The Nationals travel to Atlanta to play a three-game series against the Braves starting on Monday night. Nationals right-hander Zach Day will get the start in Game 1 and hopes to have better luck against Atlanta this time around. He is 1-4 with a 10.27 ERA against the Braves in his career.
Last Wednesday against the Phillies, Day had a 2-0 lead after five innings, but gave up three runs in the bottom of the sixth, including Pat Burrell's two-run homer. Day was taken out of the game and didn't figure in the decision.