To make room for Traber on the 40-man roster, the Nationals transferred first baseman Nick Johnson from the 15-day to the 60-day DL.
For now, Williams will not need surgery. He hopes to be throwing within 10 to 14 days, or when the pain goes away.
Even though he was getting hit hard on Tuesday night against the Braves, the shoulder didn't give Williams any problems until he gave up his fourth consecutive single to Andruw Jones in the third inning. Williams said he felt a pull inside the shoulder and knew he had to come out of the game.
"I'm just sore," Williams said. "I woke up this morning, I was sore. I went to the doctor -- sore. I have that real tired feeling. I have to stay positive. I have to work my butt off and try to come back. That's what I'm going to do."
With Williams out of action, Washington will insert reliever Micah Bowie into the starting rotation. Bowie last pitched on Tuesday and threw 47 pitches in two innings. The team plans to stretch him out to about 70 pitches on Sunday against the Orioles. Manager Manny Acta said Bowie is not as resilient when it comes to pitching back-to-back days as a reliever.
Bowie was informed of his new role on Wednesday. He hasn't started a game since 1999, when he was with the Cubs. Elbow reconstruction surgery and a shoulder adductor strain forced him into the bullpen.
"With Jerome being out, if I could help the team, I'm more than happy to do it," Bowie said. "Anytime you could take the ball and start the game, that's an awesome thing. As pitcher, it's something I love doing. It's something you always strive for."
Traber will join Ray King as one of the lefties out of the bullpen and it appears that his days as a starter in a Nationals uniform are over. They like the fact that he didn't give up a run in 7 1/3 innings out of the bullpen last year.
Traber played in 10 games for Columbus and was 1-2 with a 2.60 ERA. He walked only four and struck out 16 in 27 2/3 International League innings.
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Injury report: Right-hander John Patterson, on the disabled list because of right elbow and biceps soreness, played catch on Tuesday and threw from 75 feet. Patterson said he didn't feel any pain.
"I was just good to go out there and throw. I'm trying to get my arm going," Patterson said.
The last couple of days, Patterson has seen a physical therapist to work on his neck and shoulder. Patterson said those two parts of his body could be related to the nerve problems in his elbow.
There is no timetable when Patterson will come back. Acta is hoping that it will be sometime in June.
Reliever Luis Ayala, who is still recovering from elbow reconstruction surgery, threw 16 pitches on Tuesday in an extended spring game and didn't feel any pain. Ayala will throw one inning on Friday and then two more innings on Monday. There is no timetable when he will return, but the team hopes he will be back sometime in June.
Ayala has not pitched in a game since September 2005.
Have a seat: Acta decided to sit struggling second baseman Felipe Lopez for Wednesday's game and started Ronnie Belliard in his place. Lopez is 14-for-85 (.165) with 23 strikeouts.
Transaction: The Harrisburg Senators, the Nationals' Double-A affiliate, have been sold. The Harrisburg Senators will remain in their current location for at least 29 years under a $13.25 million agreement to sell the team to Senators Partners LLC of Northbook, Ill.
Michael Reinsdorf, a managing member of the new ownership group and son of White Sox owner Jerry Reinsdorf, said the Senators were attractive because of their membership in the Eastern League, support from the city, the possibility of renovating Commerce Bank Park on City Island and a superior management team already in place.
The sale now requires the approval of the Eastern Professional Baseball League, the National Association of Professional Baseball Leagues Inc., which is the governing body of Minor League baseball, and the Office of the Baseball Commissioner.
Closing and change of ownership will occur on or before Sept. 13.Stat of the day: Entering Wednesday's action, the Nationals' bullpen has a 3.88 ERA. Since April 29, the bullpen has a 2.45 ERA.
Did you know: Jones has hit 46 home runs against the Nationals/Expos during his career. The Phillies rank second in giving up the most home runs to Jones, with 37.
Coming up: The Nationals play the fourth game of a four-game series against the Braves on Thursday afternoon. Washington left-hander Matt Chico (2-4, 5.59) will face Braves left-hander Chuck James (4-3, 4.04) at 1:05 ET.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.