Cespedes has been on the disabled list since May 12, retroactive to May 7, with a strained muscle in his left hand. He went through a full pregame workout on Sunday for the first time since getting injured. Oakland manager Bob Melvin said that everything went well, and Cespedes will begin a rehab assignment with Triple-A Sacramento on Monday.
The rookie could be activated from the DL in time for the A's series against the Royals, which begins in Kansas City on Friday.
"I think that's probably reasonable, but you don't want to put timetables on him like that," Melvin said.
The 26-year-old Cespedes was leading Major League rookies with 21 RBIs and four stolen bases before the injury, and was tied for the lead in home runs with five.
After not doing much baseball activity in the period right after his injury, Cespedes' recovery has accelerated greatly. He still hadn't swung a bat when the week began, but he gradually progressed through several rehab steps, from light-intensity hitting in the indoor cage to full-intensity dry swings and, finally, batting practice on Saturday.
"Physically, he's been keeping himself in great shape," Melvin said. "We've been waiting for when he's been able to swing the bat with no complications. [The hand] feels 100 percent, so I don't think we're rushing that."
To prevent future problems with the muscles in his hands, Cespedes ordered new, tapered bats, and has said he plans on changing his grip -- he'll no longer wrap his left hand around the knob at the base of the bat.