MILWAUKEE -- Cubs first baseman Anthony Rizzo was scratched from Friday's lineup against the Brewers because of tightness in his lower back and is listed as day to day. Manager Joe Maddon said Rizzo may also skip Saturday's game against the Brewers.
"It's just that tightness, back tightness," Maddon said Friday. "He did a lot of extra hitting [Thursday], and that might have brought it on. It's definitely a day-to-day kind of thing. Definitely today. It's possible [he'll sit] tomorrow, too."
Rizzo was off to a slow start, with three hits in 28 at-bats so far. He is three hits shy of 900 in his Major League career, and four doubles shy of 200 in his Cubs career.
Victor Caratini started at first base in Rizzo's place on Friday and went 1-for-4 with an RBI in the Cubs' 5-4 loss.
• Jason Heyward hit his first home run of the season on Thursday, launching a 3-2 pitch from Milwaukee's Corey Knebel 375 feet to right. Heyward's swing has been over-analyzed since he signed with the Cubs and batted .230 in his first season in 2016.

"From my perspective, and everybody concurred when they looked at the video, he really drew his hands inside that ball to present the barrel of the bat," Maddon said of Heyward's homer. "If he's able to get that feel, it will make a big difference, as opposed to presenting the weak part of the bat to the ball. [We want him to] present the stronger part of the bat to the ball by drawing his hands in. It was good to see that.
"I liked what he did, and I think he's been making some nice adjustments," Maddon said. "I think you'll continue to see a positive trend."
It was Heyward's only at-bat in the game, as he had entered as a defensive sub.
"It was good to be rewarded with a good at-bat," Heyward said. "I feel like I've been having good at-bats. [Knebel] made some good pitches. He threw a fastball inside, and I put a good swing on it."
Watching the video of Heyward's homer, you can see hitting coach Chili Davis passively watching from the dugout while Cubs players are excited.
"He played, so he knows what it feels like," Heyward said of Davis. "He's been saying that all along, all spring -- 'I ain't worried about you.' That's good, because I'm not worried about me."
• The Cubs will be at Wrigley Field for the first time this season on Monday when they play host to the Pirates in their home opener. Benjamin Zobrist's wife Julianna will sing "God Bless America," and Wayne Messmer will sing the national anthem.
Hall of Famers Andre Dawson, Fergie Jenkins, Ryne Sandberg and Billy Williams will throw out ceremonial first pitches, and members of the Loyola Ramblers men's basketball team, which reached the NCAA Final Four, will lead the crowd in the seventh-inning stretch.
The forecast calls for unseasonably cold weather in Chicago.
"I've played in snow, sleet, all that stuff, hail in D.C., Colorado," Heyward said. "When you're going through it, it could be cold or whatever, but at the same time, it's still fun and something different to keep it from being 'Groundhog Day.'"