Rivera, 33, was designated for assignment by Toronto on July 3. Prior to that, he appeared in 70 games for the Blue Jays this season, batting .243 with a .305 on-base percentage, six home runs and 28 RBIs.
The right-handed-hitting Rivera posted a .327 average and .400 on-base percentage in 65 plate appearances against lefties this season, but struggled against right-handers, hitting just .219 in 192 at-bats.
Rivera was acquired by Toronto in a January trade that sent outfielder Vernon Wells to the Angels in exchange for Rivera and catcher Mike Napoli.
Adam Berry is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.