SAN FRANCISCO -- The D-backs activated outfielder Mark Trumbo from the disabled list Friday and optioned Roger Kieschnick to Triple-A Reno.
Trumbo had been on the DL since April 22 with a stress fracture in his left foot.
Initially the D-backs planned on activating him after the All-Star break, but with Trumbo swinging the bat well -- he hit a combined .458 with five homers and 12 RBIs in seven rehab games in the Arizona League and Reno -- they decided to activate him for the series with the Giants.
"I was contributing a little bit down there and I think the thought was that it would be nice if I was able to do that up here," Trumbo said. "Obviously there's no guarantees. It's one of our division rivals and if I can help the cause up here, we'd be that much better for it."
Trumbo did not play a full nine innings during his rehab stint, and D-backs manager Kirk Gibson said he will treat these next few games like an extension of the rehab. Trumbo will start Friday and Sunday, but will get Saturday off, and should the games drag on, Trumbo will likely be removed early.
"Baseball-wise, he's ready," Gibson said. "We had certain things that we were looking for. Initially, we didn't think he probably was, but he's really come on strong right now, recognizing pitches much better. He's done everything we've asked and everything we've needed him to do."
Trumbo went 1-for-4 with a strikeout Friday, singling in the seventh for one of the D-backs' three hits off Tim Lincecum in a 5-0 loss.
Steve Gilbert is a reporter for MLB.com. Read his blog, Inside the D-backs, and follow him on Twitter @SteveGilbertMLB. This story was not subject to the approval of Major League Baseball or its clubs.