Cousins was picked up by the Mariners while Herndon is set to join the Yankees. Both players previously had been claimed off waivers by the Blue Jays in late October.
Toronto has been aggressive on the waiver wire during the early stages of the offseason. The club made six waiver claims in October with the main goal of attempting to sneak the players through at a later date to build depth in the Minor Leagues.
That didn't work in this case, but ultimately won't cost the Blue Jays anything in the long run. Both players had already been removed from the 40-man roster and the Blue Jays currently have one remaining spot on that list.
Cousins has hit .183 with nine RBIs in 175 career at-bats in the big leagues. Herndon allowed four earned runs in 7 2/3 innings in Philadelphia last season. The 27-year-old is coming off Tommy John surgery and is not expected to be available until at least June.