"It had a bit to do with his last game with the Giants," manager Bob Melvin said of the team's decision. "We have some options, and certainly the way he pitched, hopefully he can try to ride that confidence into his next start."
Right-hander Jesse Hahn was another option, but the A's will keep him at Triple-A Nashville to iron out the issues that led to an 11.15 ERA during Spring Training.
"The way Surkamp pitched," Melvin said, "he deserves to pitch Friday."
Surkamp, 28, will join the A's in Oakland on Thursday in time to travel with them to Seattle, but he won't be activated until Friday, at which point the club will have to make room on its 40-man roster.
Surkamp pitched in just one big league game in 2015, a 3 1/3-inning relief outing for the Dodgers. He has a 6.47 career ERA across 57 innings with the Dodgers, White Sox and Giants.
• Infielder Eric Sogard is still being bothered by a neck strain when he hits, so he's expected to continue his rehab in Oakland when the A's go to Seattle.
• Mark Canha made just his second career start in right field on Wednesday, lending regular Josh Reddick a break against left-handed pitching.
Jane Lee is a reporter for MLB.com. Follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.