"He came down [into the dugout] later in the game and would have been available to pinch-hit," manager Clint Hurdle said. "So maybe it's not as bad as it looked. We'll know more [Sunday]."
Harrison told MLB.com, "I'm fine," as he made a hasty departure from the clubhouse following the long day of baseball.
Harrison had just shifted from third base to shortstop when Matt Szczur led off the Cubs' 11th with a flare to left-center off John Holdzkom. Harrison ran down the ball for an over-the-shoulder catch, and spun around to make a flamboyant toss back into the infield.
He appeared to land awkwardly, and he began hopping on his right foot as teammates and trainer Todd Tomczyk surrounded him. A few minutes later, Harrison limped off the field.
Harrison's game-winner was his fourth hit of the game, and it gave him the National League batting lead with an average of .315. Philadelphia's Ben Revere trails by one point.
On Aug. 8, in the game against the Padres at PNC Park, Harrison attempted to steal second and San Diego shortstop Everth Cabrera landed atop his left ankle. The joint has been tender ever since.
Brent Morel started at third base in Saturday's regularly scheduled game.
Tom Singer is a reporter for MLB.com and writes an MLBlog Change for a Nickel. He can also be found on Twitter @Tom_Singer. This story was not subject to the approval of Major League Baseball or its clubs.