Joe Girardi has not ruled out using Hideki Matsui in the outfield when the World Series shifts to Philadelphia on Saturday night.

Matsui has been used as a designated hitter all season because of a bad knee, but for the games played in Citizens Bank Park there will be no DH with the pitcher in the lineup.

“There’s a possibility,” Girardi said. “It’s something that we will discuss. There’s the old double-switch sometimes in the National League that you might do. We’ll take a look at it every day.”

Girardi said earlier this postseason that Matsui had tested his knee in the outfield before the team’s interleague schedule, but it swelled up, so they decided to play it safe and use him as a pinch-hitter. But with the season almost over that might limit the risk for the Yankees manager.

“The one thing about Matsui is the thought process, you see how he’s running, and you know you don’t necessarily have to keep him healthy the next two or three months,” Girardi said of Matsui, who is a free agent at the end of the season. “You’ve got to keep him healthy for about 10 more days, and it’s something we’ll have to think about it.”

If Matsui does forge his way into the lineup, Girardi would have an interesting decision on who to keep out. Johnny Damon plays left field, where Matsui played for most of his Yankees career, but Damon is as critical to the Yankees lineup as Matsui. Girardi could toy with moving Damon to center and taking out Melky Cabrera, but then the team’s defense suffers. The most likely scenario might be to move Damon or Matsui to right field to replace Nick Swisher, who has struggled at the plate this postseason.

When asked if he would test the knee in the next few days, Matsui said there was no need for that.

“It’s not like I can’t play the outfield, but it’s really a manager’s decision if he wants me out there or not,” Matsui said through his interpreter.

But Matsui said he has no problem being used as a pinch-hitter.

“I have no frustration about that. It’s a role I have to accept,” he said.