The plan is to have Doolittle pitch again for Nashville on Wednesday and Saturday, before potentially being activated when the A's return home for a three-game series with the Indians.
Doolittle, sidelined with a left shoulder strain for nearly two months, faced hitters Friday for the first time since going on the disabled list. Melvin said Doolittle "felt great" after the 20-pitch session against teammates, which was enough to signal the green light for a rehab outing.
"He was all for it," Melvin said. "He's a hard-working guy, and he's honest too. If we didn't feel like after his bullpen that he felt great, then we wouldn't do this."
Right-hander Jesse Hahn (strained shoulder) could return even sooner than Doolittle. He threw a 30-pitch bullpen session on Saturday and is expected to go out on a rehab assignment this week ahead of a potential start in Chicago on Aug. 21.
Jane Lee has covered the A's for MLB.com since 2010. Follow her on Twitter @JaneMLB. This story was not subject to the approval of Major League Baseball or its clubs.