Bumgarner's linescore elaborated for him. He allowed a pair of runs while yielding two hits and walking one in the first inning, then left the game. Looking vulnerable wasn't an issue for Bumgarner, whose goal was to build arm strength.
"It's just good to get back out there at this point," Bumgarner said. "Obviously, you'd like to have good results every time you get out there. But it's good to be back out there and face some hitters. It's as close to a meaningful game as you can get."
Giants manager Bruce Bochy hasn't officially named Bumgarner the starter for the April 2 regular-season opener at Arizona. But that's a mere formality.
"It's about getting ready for the regular season," Bumgarner said. "As long as you feel like your arm strength's there and your pitches are ready by the end of this month or six weeks, that's all you can ask for."
Catcher Nick Hundley, who started Friday, demonstrated the physical and mental expertise that led the Giants to acquire him during the offseason.
In the first inning, he nimbly sprang from his crouch to gobble up Bumgarner's initial pitch to Adam Duvall, a curveball that bounced several feet in front of home plate. With a Reds runner at third base, Hundley's pickup temporarily saved a run.
"That was a tough pitch to block," Bumgarner said. "I pulled it a little bit. I was impressed with it."
Hundley also guided right-hander Clayton Blackburn through two scoreless innings. Though they had never worked together, Blackburn shook off Hundley just once.
Hundley revealed that, after signing with the Giants as a free agent, he requested videos of the pitchers on their 40-man roster so he could study their tendencies. He also gained access to an application that had more file footage of San Francisco's pitchers.
"I don't want to come in blind," Hundley said. "I want to put these guys in the best possible position to be successful."
Referring to Blackburn, Hundley added, "He's fighting to make the team and do great things in his career. If I'm in the way of that, that's a detriment. So it's my job to help these guys out and see how good they can be."
• Blackburn reasserted himself as a candidate for the No. 5 starter's spot with his outing. He said that he threw less this offseason than he did in the winter of 2015-16, after he won the Pacific Coast League ERA title but struggled in Spring Training. Blackburn admitted that overtraining might have accounted for his struggles last season, when he finished 7-10 with a 4.36 ERA for Triple-A Sacramento.
• Shortstop Orlando Calixte impressed Bochy with his ninth-inning leadoff walk that preceded Chris Marrero's game-winning homer. Calixte, who appeared in two games with Kansas City in 2015, can play second base and third base as well as the outfield.
"He'll get a good look," Bochy said.
Chris Haft has covered the Giants since 2005, and for MLB.com since 2007. Follow him on Twitter at @sfgiantsbeat and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.