Schafer missed Tuesday's game with an oblique injury, the first game he had missed this season.
"We didn't need to push him," said manager Brad Mills. "He said he'll be fine on Friday."
Schafer was 0-for-1 with two walks prior to exiting, extending his streak of reaching base to start the season to 24 games.
"I don't feel too good right now," said Schafer. "I'll be fine by Friday."
Richard Dean is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.