Left-hander Sammy Solis was placed on the disabled list Monday with "shoulder fatigue," according to Nationals director of player development Doug Harris.
Solis is 0-0 with a 3.38 ERA in four starts for the high Single-A Potomac Nationals. He has thrown 16 innings and allowed 15 hits, six earned runs, five walks and nine strikeouts.
In a text message, Harris said Solis' injury "does not appear significant at this point. He's been working very hard and will benefit from a few days off. We don't expect this (disabled list stint) to be lengthy."
Solis returned from rehabbing Tommmy John surgery on May 21. He underwent the procedure on March 6, 2012. His last two starts have been his longest outings, totaling 10 innings.
Solis was ranked the Nationals' preseason No. 8 prospect by Baseball America.