In his first appearance, the 36-year-old pitched one scoreless inning on just five pitches, but he said he still isn't quite ready to rejoin the Major League club.
"The arm strength is still not there, but that will eventually come," Farnsworth said.
Farnsworth added he'll probably make "six or seven" appearances and hopes to be back during the team's final home stand in June, which begins against the Tigers on June 28.
The righty hasn't pitched at all for the Rays this season. A year ago, he made 63 appearances and recorded 25 saves for Tampa Bay with a 2.18 ERA. Current closer Fernando Rodney has done well in his absence and holds a 0.94 ERA with 18 saves already this season.