"Sick enough that he can't play," manager John Gibbons said. "It hit him yesterday before the game and today he's feeling worse."
Rasmus is batting .223 with 16 homers and 37 RBIs in 93 games this season. He's eligible for free agency at the end of the year and isn't expected to return to Toronto.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. This story was not subject to the approval of Major League Baseball or its clubs.