Strickland hasn't allowed a run in three relief appearances spanning three innings so far.
Left-hander Steven Okert, who began the season with Triple-A Sacramento, is expected to replace Strickland on the active roster.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.