Patterson said he was pain free during the game, but his mechanics were off. He believes it's the reason he threw too many pitches and lasted just the three innings.
"Overall, not bad. I didn't feel any pain or anything like that," he said by phone late Thursday night.
Patterson said he is tentatively scheduled to have another rehab assignment in five days, but he plans to talk to the Nationals before making a final decision. There is no date as to when Patterson will rejoin the 25-man roster.
The All-Star break: Right-handers Collin Balester and Emiliano Fruto will play in the Futures Game next month in San Francisco. Balester, who is considered one of the Nationals' top pitching prospects, is 2-5 with a 3.43 ERA for Double-A Harrisburg, while Fruto, acquired from the Mariners in the Jose Vidro trade, is 3-2 with a 3.22 ERA for Triple-A Columbus.
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.