"I rolled it pretty good," Lee said. "It takes a lot to get me out of a game. I felt like I needed to come out. I'll see how I feel tomorrow."
The injury occurred when Lee planted his foot awkwardly while trying to retrieve a low throw from third baseman Chris Johnson, who had fielded a slow roller from Reds shortstop Zack Cozart leading off the inning. Matt Downs replaced Lee at first base.
Lee's ankle was visibly swollen after Friday night's 6-4 win.
"He'll be out for a couple of days," Astros manager Brad Mills said. "He received treatment the whole game. He sprained it really good." X-rays taken of Lee's ankle were negative.
Lee has been red-hot, going 7-for-7 with a home run and four RBIs in his past four games.
Jeff Wallner is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.