Braun was first bothered by the injury in Friday night's game and was forced to bunt for a base hit in the seventh inning Saturday because he couldn't swing the bat. He had to make a throw from right field in the eighth inning and came out of the game prior to the top of the ninth.
"Day-to-day," Braun said of his status. "We'll see what tomorrow brings."
Braun has dealt with a similar injury a couple of times previously in his career. The intercostal muscles make up the wall of the chest and run between the ribs.
If Braun and Segura are unable to play in Sunday's series finale against the Cubs, the Brewers will have just two players available on the bench with reserve catcher Martin Maldonado still suspended. Elian Herrera would have to start for Braun in the outfield and Jeff Bianchi at shortstop for Segura, leaving Milwaukee with both of its emergency backup catchers in the lineup.
The bench players will likely be the other half of the platoon at first base and second base.
"We'll have a two-man bench and see what they can do," Brewers manager Ron Roenicke said.
Estrada shines: There are outings when it's hard to tell how well a pitcher threw based on his final stat line, and Saturday was one of those nights for Marco Estrada.
While allowing just three earned runs in 7 2/3 innings is a good start, Estrada was as sharp as he's been in quite some time to pick up his second win of the season.
Estrada retired the first 10 batters he faced before allowing a solo home run to Luis Valbuena in the fourth inning and then sat down 10 more in a row before allowing a two-out single to Starlin Castro in the seventh.
The only pitch Estrada wanted back Saturday hurt him in the eighth inning, as Cubs catcher Wellington Castillo connected for a two-run home run to cut the Brewers' lead to 5-3 and prevent the right-hander from getting through eight innings.
"That's the best I've felt since spring training," Estrada said. "I was feeling really good in spring training and the last couple games I just haven't felt like myself. Today I did. I gave up two home runs, but I think only one was a terrible pitch. It was a pitch I didn't want to throw and still went with it. I wasn't committed to it and I threw it. That's what's going to happen."
Estrada has now given the Brewers a quality start in four of his five outings this season, and he missed a quality start by just one out in his first start of the year. The Brewers' starting staff has delivered a quality start in 19 of the team's 24 games this season.
"Estrada was outstanding," Roenicke said. "The last inning, he made a couple of bad pitches but before that, that's as good as I've seen him pitch or make pitches. Fastball, changeup, curveball, he really kept guys off-balance. He did a great job.
"Really, that's as good as I've seen him throw. It's too bad he gave up the other two runs because of the way he was throwing the ball."
Although the Castillo two-run home run was clearly on his mind after the game, Estrada said it was hard to stay mad too long because the Brewers won the game to improve to 18-6.
"Even if you give up more runs than I did today, if the team wins, you have to be happy," Estrada said. "I'm happy with the way I pitched today. I didn't like that one pitch I threw where Castillo hit it out. It wasn't on my mind to throw it. I wasn't committed. It's upsetting, but we won."
K-Rod keeps rolling: Continuing what has been an outstanding month, Brewers closer Francisco Rodriguez worked a perfect ninth inning Saturday to set a new franchise record for saves in March and April with 11.
No other reliever in baseball has more than eight, as former Brewers closer John Axford is among eight pitchers with eight saves.
With the save Saturday, Rodriguez moved past Robb Nen for sole possession of 18th place on the all-time saves list with 315.