Anderson threw 20 pitches to Minor Leaguers at the A's complex in Phoenix.
"Everything went well, and he'll be on a five-day rotation, throwing to hitters again. So he's taken the next step," A's manager Bob Melvin said. "He felt good. They said the ball came out of his hand nicely. As far as his arm and elbow have gone, we've had, knock wood, no complications. I know he feels really good."
Anderson underwent surgery last July 14 and appears to be on track to return in July. Melvin was asked about the chances of Anderson rejoining the A's before the All-Star Game, scheduled for July 10.
"I don't want to put a timetable on that," Melvin said. "I think we originally said maybe late July or something like that, early August to be conservative. I don't know where that's going to go, but I know that he has been on schedule -- if not slightly ahead. But it's really tough to forecast that. It's going to be all about how he feels each and every time."