"It's been bothering him for a while, so I figured if I could give him two days here, yesterday and today, maybe it knocks it out," Girardi said.
Headley couldn't identify the cause of the tendinitis, noting that the only recent change he's made was a switch to metal cleats from his usual rubber ones after he found it harder to dig into the batter's box.
"I don't know if that's what aggravated it, but that's the only thing that was different," Headley said.
If Headley has been dealing with soreness for a while, it hasn't impacted his play. He's hitting .294/.400/.588 over his last five games.
Headley said the soreness came to a head on Wednesday after a rain-delay-lengthened 7-4 loss to the Blue Jays. While he expects the soreness to linger even after he's returned to the lineup, a team doctor has assured him there isn't a significant risk of further injury to the ankle.
"Definitely feel like I can play. I'm available," Headley said. "A little bit of time can hopefully knock it out a bit more. It's Achilles tendinitis, so there's really not a set timetable."
Brett Gardner also found himself out of Friday's lineup due to a lingering ankle injury, but Girardi said he hopes the outfielder can return Saturday. The manager reported that Gardner had no problems running in a straight line, but turning was "a little problematic for him."
Jack Baer is a reporter for MLB.com based in Los Angeles. This story was not subject to the approval of Major League Baseball or its clubs.