St. Claire speculated that mechanical changes caused by a back spasm suffered the morning Armas faced the Brewers on June 4 could have led to his arm problems.
"Lot of times, if your back is bothering you, you favor something else. The other part of the body starts taking over. You just never know for sure," St. Claire said.
With Armas expected to miss a turn or possibly more, look for right-hander Shawn Hill to remain in the rotation for a while. There was a possibility that Hill would be sent down or demoted to the Minor Leagues because of the return of John Patterson.
As for Johnson, he hasn't played since Saturday against the Yankees, and he is hoping that he can play against the Orioles this weekend, but he may be out a while.
"It may be [a long time]. This is something [that affects] you in everything you do as far as baseball is concerned -- your movement, playing defense. There's no way you can get around it," manager Frank Robinson said.
If Johnson is put on the disabled list, it will mark the seventh consecutive year in which he was shelved for a long period of time. Last year, he was on the DL because of a right heel contusion.
Injury report: Before Tuesday's game, Alfonso Soriano was seen with an ice wrap around his right hand. He said it has been sore since he took batting practice in the cage on Monday. Soriano insisted the sore hand is not the reason he struck out three times against the Red Sox that night.
"It was a bad day. It was not because of my hands," Soriano said.
Bergmann gets call: The Nationals recalled right-handed pitcher Jason Bergmann from Triple-A New Orleans. A member of the Nationals' Opening Day 25-man roster, Bergmann rejoins the Nationals for a third time this season. In 19 appearances with New Orleans, Bergmann was 4-1 with four saves and a 2.27 ERA. Bergmann, 24, allowed the Red Sox two runs on four hits in 2 1/3 innings of work on Tuesday night.
In his last stint with New Orleans, Bergmann was long and middle relief, a setup man and closed games out on occasions. Bergmann played the role of a long man on Tuesday as he entered the game against the Red Sox in the second inning.
Bergman wasn't the only one who pitched well. The Nationals thought about brining up right-hander Roy Corcoran, who is 1-1 with a 1.93 ERA and five saves for New Orleans. He has Major League experience having played for the Expos in 2003 and '04.
"Corcoran was given serious consideration, but [New Orleans pitching coach Steve] McCatty recommended Bergmann," Bowden said.
What's this? Robinson put Marlon Anderson at cleanup against Tom Wakefield on Tuesday. The last time Anderson hit cleanup was in Little League. Robinson put Anderson there because he doesn't strike out a lot and gives the Nationals some speed.
Quote of the day: "We might as well buy an apartment. When I'm down, he can stay there, when he's down I can stay there. Maybe we can split the cost." -- Bergmann, on him and Brendan Harris splitting between the Nationals and New Orleans
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Coming up: The Nationals play the third game of a three-game series against the Red Sox at Fenway Park on Wednesday night.
Hill will get the start for Washington, while left-hander Jon Lester takes the hill for the Red Sox.