In his next start, Armas pitched four innings and gave up seven runs against the Braves.
Manager Frank Robinson then announced that Armas would work out of the bullpen, but the righty didn't pitch in another game. Instead, the Nationals sent Armas to see Dr. John Conway in Dallas, Texas, where it was discovered that Armas had tightness in his right shoulder capsule. Dr. Conway didn't rule out surgery on the shoulder after the season.
The team was hoping rest would cure his ailments, but Armas still has problems with his range of motion.
Armas, who made $2.2 million this season, may have played his last game in a Nationals uniform. He is a free agent after the season, and it's questionable whether the team will offer him a contract.
Armas has logged time on the disabled list three years in a row because of shoulder problems, the worst coming in 2003, when he suffered a torn rotator cuff and labrum.
As for Spivey, he has not played since early June due to a fractured right radius, which he injured in the batting cage in Philadelphia. Spivey has been working out with the Nationals in recent days and is expected to serve mostly as a pinch-hitter, pinch-runner and defensive replacement down the stretch.
Hitting funk: Right fielder Jose Guillen is 7-for-44 with just five RBIs during the month of September and has seen his batting average dip from .304 to .291.
Hitting coach Tom McCraw said Guillen has too much of a hitch in swing.
"Guillen is wrapping the bat and trying to hit the ball too hard. You can't wrap the bat with all that motion and be quick. Hitting is bat speed." McCraw said.
Guillen feels his problems stem from putting too much pressure on himself.
"I've been leaving a lot of people on base," Guillen said. "I don't want to hear players say they don't put pressure on themselves. ... You try to do so much [at the plate].
"I'm not going to let my people down. I know a lot of people are counting on me. You can count on this: Jose Guillen is going to come through in a good situation."
More on Guillen: The right fielder said he still hasn't heard from the league office about throwing four bats, some batting gloves, a batting helmet and shin guards in the direction of home plate umpire Bill Miller on Wednesday night at Shea Stadium.
Guillen was upset after being called out on strikes -- he thought the pitch was low and inside.
The slugger is hoping his punishment will be meted out next season, so he doesn't have to miss any games as the Nationals chase a postseason berth.
"I don't want to hear from them, but I know I will. They are not going to let me get away with it," Guillen said. "I take full responsibility for what happened. I'm a man, and if anybody has a problem, they can come talk to me. I did it. I did it on my own. A lot of players have done it in the past. I did not think the pitch was a strike. Should I have behaved in a different way? Yes."
Did you know? Entering Saturday's action, the Nationals are 14-8 on the road since July 31. Overall, they are 37-39 away from RFK Stadium. With five road games left, the club has a chance to post a winning record on the road for the first time since the 1994 Expos went 42-20.
Stats of the day: Nick Johnson is hitting .404 with 32 RBIs with runners in scoring position and less than two outs entering Saturday. However, he is hitting .240 with two home runs and 16 RBIs with runners in scoring position and two outs.
On deck: The Nationals play the finale of their three-game series against the Padres at PETCO Park on Sunday afternoon.
Right-hander Esteban Loaiza will pitch on three days' rest for the third time this season. He was victorious in his first two assignments on short rest.
In his last start, Loaiza pitched seven innings, allowing three runs on seven hits against the Mets. He threw 94 pitches, 63 for strikes. The Nationals needed Loaiza to go deep into the game, because the bullpen had been overworked.
The Padres will send right-hander Pedro Astacio to the mound against Loaiza.