The lefty, coming back from a strained shoulder, needed 14 pitches in Thursday's outing -- 10 of which were thrown for strikes.
"I was talking to him today for a little while about the four pitches he didn't throw for strikes, getting on him about that a little bit," A's manager Bob Melvin said, smiling. "But he feels great. We'll probably see him here pretty soon."
Doolittle was originally expected to appear in one more game with Nashville before returning to the A's, but when asked Friday if that was still the plan, Melvin said, "We'll see," hinting the southpaw could be activated sooner than anticipated.
Doolittle has appeared in just one game this season, having missed the first six weeks of the season with a strained left rotator cuff before returning to the DL just days later.
• The A's reinstated Tyler Ladendorf from the 60-day disabled list Friday and optioned him to Triple-A Nashville. Ladendorf was on Oakland's Opening Day roster and appeared in four games before being optioned to Nashville, where he endured a left ankle injury that required surgery.
Ladendorf is a strong September callup candidate barring a slow return at Nashville.
"He was a guy we felt like would be here for a while for us, especially against left-handed pitching," Melvin said. "He does a great job with his versatility, whether in the outfield or the infield. Now, for him, it's just getting comfortable after the injury and getting out on the field on a semi-regular basis. Hopefully he plays well enough to where we can get him back here."
• Brett Lawrie and Coco Crisp returned to the A's lineup Friday after missing consecutive games with minor injuries.
Jane Lee is a reporter for MLB.com. Read her blog, Major Lee-ague, and follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.