Farquhar was optioned to Triple-A Durham on Tuesday, Steve Carney of 620 WDAE reports.
Alex Colome's return from the disabled list meant that the Rays needed to clear a roster spot, and Farquhar's recent struggles made him a prime candidate to be optioned. He gave up two huge runs in Sunday's eventual 5-1 loss to the Tigers after Chris Archer held Detroit scoreless through 5.2 innings. Farquhar notched a 6.75 ERA over 10.2 innings before he was sent down Tuesday.