Polanco, who made his anticipated Major League debut on June 10, had just one hit in his last 30 at-bats and was benched for four games in favor of hot-hitting Travis Snider before Polanco was sent down.
"After the four-day layoff where Travis was swinging the bat so well and deserved to continue to play, Gregory looked a little rough," Pirates general manager Neal Huntington said Sunday. "... Most importantly, he's been out and competing. We look forward to getting him back. If we're going to play October baseball, Gregory Polanco is going to have a hand in that."
The 22-year-old is batting .241 with a .657 OPS in 64 Major League games this season.
Stephen Pianovich is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.