Torrealba, 34, posted a .214 batting average in 10 games with the Blue Jays after signing a minor league deal in August.
Overall this season, he is hitting .233 with four home runs in 59 games (189 at-bats) with Toronto and Texas.
Torrealba broke into the majors in 2001 with the San Francisco Giants and was released by the Rangers prior to signing with Toronto.
In his career, Torrealba is hitting .258 with 56 home runs and 323 in 841 games.
The Jays signed him to help fill the void left by injured backstop J.P. Arencibia, who has shown no ill effects since his return to the lineup.
Jeff Mathis is the other Toronto catcher. Earlier this season, he signed a two-year, $3-million contract extension with a club option of $1.5 million for 2015.
Milwaukee entered play Friday winners of five straight and 2 1/2 games behind St. Louis for the final National League wild card berth.