"I tweaked again [on Friday] and it hasn't gotten better since," Willingham said. "I didn't run Saturday or Sunday, I only ran at like 30 percent on Sunday going into second base, and so before the game I went to go run and it just really bothered me."
Willingham was replaced at DH by Trevor Plouffe, who was originally penciled in to start at third base.
Jamey Carroll started at third in Plouffe's place and batted eighth. Willingham was originally supposed to bat third in the lineup so everyone behind him in the order moved up except shortstop Eduardo Escobar, who remained the club's ninth hitter.
Rhett Bollinger is a reporter for MLB.com. Read his blog, Bollinger Beat, and follow him on Twitter @RhettBollinger. Kelly Erickson is an associate reporter. This story was not subject to the approval of Major League Baseball or its clubs.