"They're better," Girardi said after the game. "[Headley] was prepared if I needed him tonight. I told him I was going to try not to use him because I was concerned that if he went out there and his back locked up, you're talking four or five days.
"[Ellsbury] said if I needed him, I could use him. That gives me a pretty good feeling."
In their places, Brett Gardner played center and Brendan Ryan assumed duties at the hot corner.
Video: BOS@NYY: Headley fires home to cut down Betts
Girard said Headley's back "kind of locked up a little bit" after Wednesday's game.
With two integral players out, Girardi said he was hopeful that a day off would help refresh the pair. Though there has been some anticipation in the clubhouse about clinching a playoff spot, Girardi said he is more concerned about his players physically than mentally moving forward.
"I worry more about the physical than anything for the players right now just because I think they could use a day off or two, especially in the stretch that we've been in, a doubleheader that we've played," he said. "The mental part is important, but physically you want them to feel good and refreshed. So I think it's really important, let's go out and win a game tonight."
Grace Raynor is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.