Doumit was originally set to be placed on the 15-day disabled list with the injury, but was able to avoid it, as he received favorable results from an MRI exam taken on his calf.
"He was on the field hitting early and he did fine," Gardenhire said. "He's champing at the bit. He's available to pinch-hit. As long as he doesn't fly out of the box, he'll be fine. His leg feels really good. He wants to take some swings."
Doumit doesn't have the luxury of making his return as a designated hitter this weekend, as the Twins are playing without one in a National League park during this Interleague series.
Gardenhire said he originally planned to give either Joe Mauer or Justin Morneau the day off on Friday to let Drew Butera catch left-hander Scott Diamond, but both wanted to be in the lineup.
"I thought I'd catch Drew Butera because he's caught Diamond, but Interleague Play makes it different," Gardenhire said. "Mauer wants to catch. I was out there early and I asked him if he wanted a day off, but he said he wanted to play. So that's good enough for me. And Mornie, same thing."