Placed on the disabled list April 29 with a strained left calf and six games into a 10-game rehabilitation assignment, Ellis returned to the Oakland-Alameda County Coliseum to work out and take batting practice before the opener of a three-game Interleague series against the Giants.
Batting .190 (4-for-21) on his rehab stint while splitting time between high Class A Stockton and Triple-A Sacramento, Ellis will come off the DL Sunday.
"[The calf] is great," Ellis said. "It feels great. Everything feels good. I'm excited to be back."
Ellis will play his final four rehab games with Sacramento on Tuesday through Friday and take Saturday off. After six weeks of forced inactivity, he's thrilled to be back on the diamond.
"It was awful," Ellis said of his layoff. "Playing baseball, it's what we do. I was still with the [A's] on the road, but not being able to play, it's tough."
Ellis spent a good deal of his time off the field in the weight room, looking to add strength to his upper body. He'll slide back into his usual second-base slot when he returns to the A's lineup.
Adam Kennedy, who was acquired to fill in for Ellis and was batting a team-high .304 through Sunday, has been taking grounders at third base and first base. Manager Bob Geren said Kennedy could also be used in the outfield.
"The way he's swinging the bat," Geren said, "we'll find a way to keep him in the lineup."
Adam Loberstein is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.