Headley was officially reinstated from the 15-day disabled list Saturday and was in the starting lineup against the Marlins. All told, Headley missed 14 games with a right calf strain.
The Padres optioned reliever Kevin Quackenbush to Triple-A El Paso. Quackenbush tossed a scoreless ninth inning in Friday's 10-1 victory over the Marlins.
As for Headley, he strained the calf during his first at-bat against the Nationals on April 24. He then landed on the disabled list the following day.
It was the same calf that he strained during an infield drill in February in Spring Training, although this time, the injury was less severe.
"He had the calf strain the first week of camp and was fighting that throughout and the knee thing [a bone bruise] popped up before this," said Padres manager Bud Black. "My hope is he can feel better physically. I think he's heading in the right direction."
At the time of the injury, Headley was hitting .186 in 70 at-bats with two home runs, seven RBIs. He's been able to work on his swing on the side, in the batting cage and getting at-bats in games in Lake Elsinore to get him ready for his return.
"Mechanically, it feels good in the cage," Headley said of his swing. "Hopefully, I can get consistent at-bats and stop the one again, off again."
Headley had four hits in 12 at-bats in four Minor League games.
Headley said he and the training staff would monitor the calf and make sure it gets loose before each game.
"There are some things you try to stay on top of, some preventative maintenance things, trying to keep it as loose as possible," Headley said. "I wish there was an answer as to why it happened. We'll keep an eye on it. Hopefully, I'm through the worst of it."
Black would like nothing more than for Headley to find his swing and for outfielder Carlos Quentin to rejoin his teammates this week on the road. It would be the first time the team hasn't played short-handed this season.
"We're excited to get Chase back," Black said.
Headley gave Black and the Padres plenty to cheer on Saturday, delivering a three-run homer during a four-run sixth inning that broke open a 2-2 tie en route to a 9-3 victory. Headley finished 1-for-3 with two walks and two runs scored.