Right-hander Chad Jenkins was recalled from Triple-A Buffalo to fill Johnson's spot on the roster. Toronto had been carrying six relievers since left-hander Rob Rasmussen was optioned to Buffalo on Tuesday.
Jenkins, 26, appeared in 15 games and has a 3.72 ERA and 10 strikeouts over 19 1/3 innings. He likely will split long-relief duties with fellow righty Todd Redmond and also could make some spot appearances in middle relief.
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.