"Do I think we'll get him in 15 days? No," Girardi said. "Do I think it'll be a real long DL stint? No. But as I've said all along, it's going to depend on how he responds to the treatment, and with speed being a big part of his game, we just have to see how he's doing."
Ellsbury sustained the knee injury while swinging at a fourth-inning pitch on Tuesday against the Nationals in Washington. The Yankees added rookie outfielder Slade Heathcott to the roster to take Ellsbury's spot and also plan to use veteran Chris Young in center field.
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch, on Facebook and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.