Making his first start in a month, the right-hander will try to prevent the Brewers from an eighth straight defeat and a three-game sweep at the hands of the Chicago Cubs on Wednesday night at Wrigley Field.
Milwaukee (73-65) led St. Louis by 2 1/2 games in the NL Central on Aug. 19, but now trails the Cardinals by two after losing for the 10th time in 12 contests, 7-1 on Tuesday.
The Brewers, who own a 1 1/2-game lead for the second wild-card spot, have been outscored 49-14 during the seven-game skid. They last dropped eight straight as part of a nine-game slide May 10-19, 2010.
"We have to get back to the way we played the majority of the first five months," said star Ryan Braun, who is 4 for 25 with 12 strikeouts in the last seven that all have come on the road. "We have to go out there and continue to compete every day and it will turn around at some point."
The loss of All-Star Carlos Gomez for at least a week with a sprained wrist doesn't help matters. However, the return of Garza (7-7, 3.58 ERA) from a strained oblique could give the club a boost.
"I'm fine - healthy, strong and just glad to be able to pitch in again," he told MLB's official website.
Milwaukee starters have a 6.21 ERA during the losing streak, but Garza has allowed two or fewer runs five times in his last six starts and two with eight hits over 21 innings while going 1-0 over the last three. He gave up a hit and no runs before leaving with the injury in the sixth inning of a 3-2 loss at St. Louis on Aug. 3.
Garza, who went 21-18 with a 3.45 ERA in 60 starts for the Cubs from 2011 until they traded him to Texas last season, is 1-1 with a 3.21 ERA against his former team this year.
He's 12-8 with a 2.74 ERA in 29 starts at Wrigley.
Garza won't face Anthony Rizzo, who could be done for the season with a strained lower back. The All-Star first baseman is batting .278 with 30 home runs and 71 RBIs, but hasn't played since last Tuesday.
"We're going to be cautious with him," Cubs president of baseball operations Theo Epstein said. "I think we'll see where we are down the road."
Teammate Starlin Castro is 2 for 6 against Garza and batting .406 in nine games, but also could sit after he injured his left leg sliding into home plate Tuesday.
A winner in 11 of 17 and looking for its first three-game home sweep over Milwaukee since Aug. 23-25, 2004, Chicago hopes Kyle Hendricks (5-1, 1.91) continues the strong start to his career.
Since allowing four runs in six innings of a 6-4, 12-inning win at Cincinnati in his major-league debut July 10, Hendricks has yielded eight earned runs in 50 2-3 innings over the next eight. The right-hander allowed two runs without earning a decision in the 7-2 victory at St. Louis on Friday as the Cubs won their sixth straight with him on the mound.
Hendricks gave up six hits over 7 1-3 innings of a 3-0 home win over the Brewers on Aug. 12.
Fellow Chicago rookie Jorge Soler is 11 for 22 with eight RBIs in six games since his major-league debut last Wednesday.