The American League's Player of the Week for the period of April 7-13, Beltran has batted just .186 (11-for-59) in 14 games since the game against the Rays.
"He swung the bat really well in Boston after that, but I've thought about that, wondering could there be something there," Girardi said. "He says he feels good and doesn't get a lot of treatment, but I still wonder about it."
Beltran has three hits in his last 15 at-bats entering play on Friday and went 1-for-6 in two games against the Angels on this road trip.
"I thought he had some decent at-bats in L.A. that last game. He's due," Girardi said. "He's just going through what other guys have gone through over the course of a season. Eventually you get even, and that's the fun time for a hitter."
Bryan Hoch is a reporter for MLB.com. Follow him on Twitter @bryanhoch and read his MLBlog, Bombers Beat. This story was not subject to the approval of Major League Baseball or its clubs.