Both Ryan Braun and Aramis Ramirez were out of the lineup at the start of Sunday's 6-5 loss to the Pirates, although Braun did make an unsuccessful pinch-hit appearance in the eighth inning.
With catcher Jonathan Lucroy on the disabled list, it meant the Brewers played most of Sunday without their top three run producers.
Brewers manager Ron Roenicke offered nothing definite about the availability of Braun and Ramirez for Tuesday's game.
"We'll see where they are Tuesday," Roenicke said. "It's been a weird season so far. I still think, with the pitching staff and whoever we put out there [that the Brewers can win].
"I still think we can compete with the team that we have. Yes, people need to step up and play well, but I still feel good about it."
Asked after Sunday's game if they thought they would play Tuesday, Braun was cautious and Ramirez was confident.
"I hope so," Braun said.
"I should be good for Tuesday," Ramirez said.
The Brewers will face Cubs right-hander Ryan Dempster, who is 0-3 but has a 2.90 ERA and may have been the Cubs' best starter this season.
Dempster got a no-decision in his last outing Wednesday against the Padres, keeping the 35-year-old veteran winless since Aug. 11 of last season, a span of 18 starts.
He is the first Cubs starter to go 18 consecutive starts without a victory since Danny Jackson from 1991-92, according to STATS LLC.
Cubs: Road woes continue
After Monday's 3-2 loss to the Giants, the Cubs have lost 11 straight road games for their longest skid away from Wrigley Field since dropping 11 in a row from June 18-29 1954.
The team's problem? "Our offense," said Cubs manager Dale Sveum. "We've got to get something going offensively. You can't win ballgames scoring one run or two runs a game, it just doesn't happen. No matter how good your pitching and defense could possibly be, you've got to put some numbers up on the board.
"The bottom line is, no matter what the lineup is, we have to sustain and keep the line moving somehow on a consistent basis and we cannot do that right now. It's very difficult, it seems, for us to have five or six real quality at-bats in a row."
Brewers: Gallardo gets the start
Opposing Dempster on the mound for the Brewers will be 26-year-old right-hander Yovani Gallardo, who is 4-4 with a 4.22 ERA in 11 starts and has had six consecutive quality starts.
In his last outing, in a 6-3 victory over the Dodgers on Wednesday, Gallardo allowed eight hits and three earned runs in six innings and also had an RBI single that drove Dodgers starter Clayton Kershaw from the game.
Nyjer Morgan homered twice in three days in the Brewers' weekend series with the Pirates, after ending a streak of 138 plate appearances without a homer or RBI to start the season Friday night.
The Brewers have used a new starting lineup in each of the last 18 games.