Ellsbury said on Sunday that he has been told to anticipate it will take him six weeks from the date of his May 19 injury, which he sustained after catching his spikes in the dirt of the batter's box at Nationals Park. In theory, that would set his target date as June 30.
"I'm optimistic I can be back before that," Ellsbury said. "If I can trim any time off that, I think it would be a success. Each step I'm pushing it and trying to trim more time off that six weeks when I can. I want to get back there. It's definitely not fun watching, that's for sure."
Ellsbury said that the sprain is to his lateral collateral ligament; he has been running on the basepaths and taking batting practice indoors before receiving treatment during the game. Ellsbury has reported some tightness in the knee, but not enough to be considered a setback.
"It hasn't slowed anything down, and I've been told that's natural," Ellsbury said. "That's nothing that's an eye-opener or anything that the doc didn't say would happen. Even with that, it's still progressing according to the rehab program."
Ellsbury could take on-field batting practice this week at Marlins Park, where the Yankees will play a two-game Interleague set that begins on Monday.
The Yankees anticipate that Ellsbury will remain in Florida after that series with the Marlins, traveling up to the team's complex in Tampa to continue his rehab and eventually get into Minor League games.
"I think the more work I do here, the less games I'll need," Ellsbury said. "I think that's the plan for everybody, but I'm definitely making progression each and every day."
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.