"Tommy just needs to go down there and do his thing," manager Bob Melvin said. "He went through a little period here recently where he hasn't been pitching great, but he's still pretty good. And when you're sending a guy like Tommy Milone down, it means you have some good pitching, and we do.
"He's been giving up some hits, and maybe his command isn't like it was earlier. [Friday] night was his worst game. He's had a couple of these in his last four. We still have a lot of confidence in Tommy. He's a big part of this team, he's just not here right now."
Friday marked the second time in his last four starts Milone went four or fewer innings. He has a 4.81 ERA over his past 14 starts after posting a 3.71 ERA during his first eight.
He'll start for the River Cats on Thursday in Omaha, Neb.
"Obviously I feel like I haven't pitched like myself lately," Milone said. "I think it could be good to go down and work on myself and work on getting back to what I think I am and what I know I am as a pitcher, and hopefully I'll be back up here soon.
"I feel like that's the kind of pitcher I am, the guy who's always consistent and tries to keep their team in the game, and I haven't been that guy. Hopefully I can get that back."
Scribner joins the A's for the third time this year but first since May 10, when he was optioned to Sacramento, where he has a 2.48 ERA in 25 relief appearances. He has not pitched in two days, giving the A's a fresh arm following Dan Otero's 42-pitch relief performance Friday.
"Throwing as many pitches as he did yesterday," Melvin said, "you get into an extra-inning game today and you don't want to get caught short.
"Scrib's pitched in any number of roles for us. He's matched up, pitched an inning later in games, pitched length for us. He's a very versatile bullpen piece."
"It's always fun to pack your whole life up in an hour," joked Scribner, who got word of his promotion early Saturday. "Down there I felt great, throwing strikes, getting ahead. It's frustrating being away from the team, but we have fun down there too. It's something I think about on an everyday basis, but I try to stay focused on doing my own thing to try to get back as fast I could."