Scribner's flight was scheduled to land at 11:30 a.m. PT, and he will be available to pitch in Thursday's rubber match against the Astros.
"We always keep close tabs on Scrib," manager Bob Melvin said. "He's not here all the time, but he is a part of this team."
The 29-year-old right-hander was on the A's Opening Day roster and made two appearances before being optioned. He was with the team again from June 17-20 but did not see any action.
In 37 2/3 innings with Sacramento, Scribner has a 3.35 ERA and an eye-opening 57 strikeouts versus seven walks.
Aaron Leibowitz is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.