Polanco aggravated his groin while running the bases during the ninth inning of Sunday's 8-0 win over the D-backs in Arizona, according to Hurdle. Polanco hit an RBI double, took third on a wild pitch and scored on a sacrifice fly in that inning.
Polanco reported to Wrigley Field on Monday afternoon and couldn't shake the tightness enough to play.
"It really wasn't loosening up, so we stayed away from him," Hurdle said.
Andrew Lambo took Polanco's place, playing right field and batting second. It was the second start of the season for Lambo, who finished 0-for-4 with a strikeout. Lambo has one hit and two walks in 24 plate appearances this season.
Polanco has hit .288/.307/.425 with one home run, seven RBIs and seven stolen bases.