Wagner is starting at second base and batting sixth in Monday's series opener against the Angels.
Since being acquired by the Blue Jays in the Yusei Kikuchi trade, Wagner went 10-for-25 with a 1.116 OPS with Triple-A Buffalo. Wagner was called up from Buffalo on Monday, and the 26-year-old will face Halos right-hander Davis Daniel in his first taste of major-league action.