Alex Gonzalez walked with one out before Constanza hit a chopper toward the right side of the infield. First baseman Carlos Pena tried flipping the ball to pitcher Ryan Dempster, but never got a handle on it. Dempster still raced to first when Constanza's right foot caught the edge of the base awkwardly.
Constanza, who was helped into the dugout, was replaced by Jason Heyward on the bases and in right field.
So far this season, Constanza is batting .372 with a pair of homers and nine RBI in 23 games. His contract was purchased from Triple-A Gwinnett on July 29.