Sheets' move to the DL, with what officially is being termed a right posterior shoulder strain, was expected. He had strained a back muscle this spring near the one he tore last August.
Sheets' assignment was backdated to March 24, and he is eligible for re-instatement beginning April 8.
Sheets is expected to travel with the rest of the team to Milwaukee for Opening Day festivities before departing for a Minor League assignment, possibly at Double-A Huntsville, where the warm weather is favorable for rehabbing players.
Sheets made two starts this spring, going 0-1 with a 27.00 ERA.
Adam McCalvy is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.