Johnny Cueto hasn't pitched for the Giants since April 28. Jeff Samardzija has been out since May 29.
Both will return to the Giants rotation this week.
After making two rehab starts with Triple-A Sacramento, Cueto will pitch Thursday night when the Giants return home to face the Cardinals.
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"Johnny's set to go. He's passed all the tests, so we checked every box off. Throwing the ball well, hasn't given up a run (with Sacramento). Bullpen went fine, he's been hitting, bunting," Bruce Bochy told the media in Colorado on Tuesday.
Cueto will be limited to around 85 pitches against St. Louis.
Samardzija, who made four rehab starts for Sacramento, is set to be activated on Saturday, according to Bochy.
With Cueto and Samardzija rejoining the rotation, Derek Holland will shift to bullpen.
San Francisco Giants
Bochy said he spoke with Holland on Tuesday about the move and the veteran lefty wasn't upset.
"He's great. He just wants to do whatever he can to help the club and understands the situation and is ready for anything. Just a great attitude about it," Bochy said.
In between Cueto and Samardzija, Dereck Rodriguez will pitch Friday.