Stammen will see the team doctor on Thursday to find out how serious the injury is. Stammen has been a workhorse out of the bullpen. He can be a long reliever or pitch in the late innings.
"I think any time it's in that part of your arm, everybody jumps to the worst-case scenario," Stammen said. "But hopefully that's not the case. … But you never know. I'm optimistic about it, and hopefully it's calmed down in a few days."
Jordan was set to start for Syracuse on Wednesday, but was told late Tuesday night that he was joining the Nationals. He figures to work out of the bullpen, which has been taxed lately.
Jordan said he hasn't felt this good since the end of the 2013 season. Last year, he was looked at as a potential starter, but he was sent down after being inconsistent on the mound. He later had bone spurs removed from his elbow.
"I'm feeling really good," Jordan said. "My command is definitely getting better. The pitches are doing well. I feel just like I did in 2013."
Even manager Matt Williams saw a difference in Jordan during Spring Training compared to last season.
"The velocity was back up," Williams said. "Every time he got a chance to start games, it was good. He usually came out of the bullpen. … So, yeah, as long as he is healthy and feeling good, his stuff is really good. He had a little bit of fatigue last year. So far the whole spring at the start of this year has been great."
Bill Ladson is a reporter for MLB.com and writes an MLBlog, All Nats All the Time. He also can be found on Twitter @WashingNats. This story was not subject to the approval of Major League Baseball or its clubs.