The Rays have designated Mike Ekstrom for assignment, tweets Marc Topkin of the St. Petersburg Times. The move clears a spot on the 40-man roster for Russ Canzler.
Ekstrom, 28, has appeared in just one game for the Rays this season, spending most of the year at Triple-A Durham, where he recorded a 4.35 ERA and 8.6 K/9 in 68 1/3 innings. The Rays claimed the right-hander off waivers from the Padres prior to the season.
The 25-year-old Canzler logged time at both infield and outfield corners for that same Durham club, hitting .314/.401/.530 in 549 plate appearances to earn the International League's MVP award.