This comes after Matsui took 45 swings off a tee Tuesday and reported nothing negative after the session.
"With this type of injury he has, you just take it day by day and hope that each step, when you come back the next day, you can take another step," Yankees manager Joe Girardi said.
Girardi said if all goes well, Matsui will progress from hitting off a tee to batting practice in Tampa.
Matsui is hitting .323 in 251 at-bats over 69 games, including seven home runs and 34 RBIs.
The Yankees have proceeded cautiously with Matsui, who has had fluid drained from the knee. General manager Brian Cashman has said there's no specific timetable for Matsui's return.
"He's not out of the woods yet, but he's certainly going in the right direction and that gives us hope," Cashman said. "Right now, that's all you can ask for on a daily basis in a rehab setting, and he's a big bat. He's a run producer that knows how to knock in runs.
"We're certainly hopeful that we can get him back. At the same time, there's no guarantee that will happen. We'll have to stay tuned."
Willie Bans is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.