Manager Rick Renteria wanted to give Rizzo a breather, and with Thursday's team off-day, Rizzo was able to rest two days.
"I could play," Rizzo said. "I don't have to take a day. Obviously, I want to be out there and help the guys win. It is what it is."
Even outfielder Chris Coghlan seemed puzzled that Rizzo was not in the lineup, joining the media with his camera phone.
"You're 24 years old -- do you think you need a day off?" Coghlan asked.
No, Rizzo said, laughing. But Renteria felt the time was right. Expect Starlin Castro to get Sunday off. The Cubs have an off-day Monday, so the shortstop would have two days to rest. Castro has made it clear he wants to play all 162 games.
"He probably wants to play 200," Renteria said. "We're just trying to be smart about their usage. If you ask any of these guys, they want to play 162 games."
Rizzo was batting .244 in 25 games in May, and this season he has fared better against left-handed pitchers, batting .315 compared with .242 against right-handers.
Rookie Mike Olt started at first base on Friday, but he had to borrow Coghlan's glove because his wasn't broken in yet.
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.