It doesn't appear that McCutchen will be out for long, though.
Manager Clint Hurdle indicated that McCutchen's status was day to day in terms of a return to the starting lineup.
McCutchen said he will be ready to start for Sunday's series finale after sitting Saturday as a precaution.
"I'm always the type of player to come into the season in tip-top shape, ready to go. It's frustrating because I want to be out there," the 2013 ML MVP said Saturday.
McCutchen left on Friday after flying out in the top of the ninth of a 6-2 win Friday night against the Brewers, the Pirates' first victory of the year.
"I was fine all game, then I took a swing and started running down the line. I felt a little weird," said McCutchen. He received treatment on Friday night and Saturday afternoon.
McCutchen is hitting .125 with a homer and two RBIs over the season's first four games. He is hitless in his last 12 at-bats.
McCutchen took a DPL -- did not play -- but wasn't about to take a DL.
"Definitely not," McCutchen said of going on the disabled list. "My leg would have to fall off for that to happen."
McCutchen's frustration is evident: "I want to be out there with nothing hindering me from performing the way I know I can," he said, "and right now I'm not there. And it's how it's been for a while. I'm trying to battle, man, do what I need to do to get that back. Treatment and a little rest will hopefully propel me into not having an issue any more."