Farquhar was designated for assignment by the Rays after Wednesday's loss to the Pirates, Marc Topkin of the Tampa Bay Times reports.
With Brad Boxberger (back) expected to return from the 60-day DL on Thursday, Farquhar was the roster casualty. The 30-year-old struggled throughout June, compiling a 6.00 ERA and 8:6 K:BB through nine innings. His past major-league experience could help draw interest on waivers.