SAN FRANCISCO >> Hayden Birdsong of the Giants came to Oracle Park Sunday knowing he wouldn’t pitch in the final game of a three-game series against the Athletics. And he’s fine with that.

Things are more uncertain with Jordan Hicks. While he doesn’t want to go back to the bullpen, he’s not going to make any waves.

Birdsong will make his first start of the season Tuesday night against the Kansas City Royals, the second of a three-game series to close out the homestand. The Giants then begin a nine-game road trip with stops in Washington, Detroit, and Miami.Giants manager Bob Melvin announced the switch Saturday.

“I’m definitely excited,” Birdsong said. “It’s what I planned to do at the beginning of the year, but circumstances didn’t let me start. But our job here is to win games.”

As a volume innings reliever, Birdsong, 23, is 1-0 with a 2.31 earned run average with 10 walks and 25 strikeouts.

Birdsong is hopeful the stint in the bullpen will pay off now that he’s back in the rotation.

“Just warming up and being ready to go all the time, it helps me learn that I need to bounce back as best I can,” Birdsong said. “I’ve learned a lot about recovery and stuff like that.”

Birdsong’s last outing was 65 pitches in an 8-7 loss to Arizona, and Melvin suggested he’d probably go 10 pitches or so beyond that Tuesday if things go as planned.

“We’re going to find out,” Birdsong said.

Melvin said Saturday that Hicks accepted his switch with the right attitude, and the 28-year-old right-hander was philosophical when speaking with reporters.

“We have a real good ballclub here, and things just weren’t going the way we wanted as a starting pitcher,” Hicks said. “So I’ve got to turn the page now and do some bullpen work. Whatever the team needs. I’m not giving up on myself. I want to be a starting pitcher. That’s what I wanted to do in the big leagues.”

Hicks was 1-5 with 6.55 earned run average in five starts. Analytics would suggest he pitched with some bad luck, with a number of seeing-eye hits. He recovered from some early struggles in games to get better as they went along -- his first-inning earned run average was 12.00, and batters hit .442 (19-for-43) in the first frame.

“I took pride in going deeper into games and getting past the five-inning mark,” Hicks said. “That’s the hardest part because that’s kind of how I was evaluating myself -- how deep I can go into games, limit damage, keep us in games. In the bad ones, I felt like I had a bad innings, ground balls that got through the infield.”

Schmitt making progress >> Utility infielder Casey Schmitt has missed 27 games with a left oblique strain but could be nearing a return. He’s 1-for-8 with Triple-A Sacramento but was at Oracle Park working out Sunday.

“The reports have been good,” Melvin said. “We’re going to see how he gets through the day and evaluate tomorrow. Could be soon. Could be a couple more days, how he gets through today will have a lot to do with that.”

Infielder/outfielder Jerar Encarnación (left hand fracture) is scheduled to start his rehab this week.