SAN FRANCISCO -- Reliever Santiago Casilla threw a second successful rehab outing for Class A Advanced San Jose on Saturday and will rejoin the Giants for the team's upcoming series against the White Sox, manager Bruce Bochy said Sunday.
"He's all set, and that's good news because when it [the injury] happened, we thought this would be longer than what it has been," Bochy said.
To create room on the active roster, the Giants optioned reliever George Kontos to Triple-A Fresno. Kontos was 1-0 with a 3.07 ERA in 11 appearances with the Giants.
"Not sure we'll need the extra pitcher with the day off plus we'll be going with the [designated hitter] so you don't use as many pitchers when you use the DH," Bochy said before Sunday's game.
Casilla's return gives Bochy a good problem to have, creating a bit of a logjam in the bullpen, with non-closer right-handers Casilla, Juan Gutierrez and Jean Machi all having strong seasons in addition to lefty Javier Lopez.
Casilla will return to his role as setup man, bouncing Machi -- owner of a ridiculous 0.29 ERA through 31 innings pitched this season -- back to more of a sixth- and seventh-inning role.
The Giants have off-days Monday and Thursday, sandwiching a two-game series against the American League's White Sox on Tuesday and Wednesday.
Casilla owns a 1.37 ERA through 26 1/3 innings. He strained his right hamstring on May 21.
Ryan Hood is an associate reporter for MLB.com. Follow him on Twitter @ryanhood19. This story was not subject to the approval of Major League Baseball or its clubs.