With Brooks Raley scheduled to make his major league debut, the visiting Cubs try to avoid a seventh consecutive defeat Tuesday night against the San Diego Padres.
While Garza was expected to return to the mound following a two-week absence, he'll instead be placed on the 15-day disabled list with a stress reaction in his right elbow and shut down indefinitely.
"We'll keep reevaluating him and will make that decision when he picks up a ball and starts throwing again," general manager Jed Hoyer told the team's official website. "To speculate right now on his status for the season wouldn't be right."
Garza's injury opens the door for Raley, who was selected by Chicago (43-64) in the sixth round of the 2009 draft. The 24-year-old left-hander went 4-8 with a 3.62 ERA in 14 starts with Triple-A Iowa.
He posted a 2.12 ERA in July and was the Cubs' minor league pitcher of the month but was hit hard his last time out, giving up six runs and 10 hits over six innings Thursday.
"He's a guy who can pitch in and out, (throws a) cutter, two-seamer, four-seamer, nothing overpowering," manager Dale Sveum said. "He's not going to probably strike a lot of guys out. He's going to pitch to contact. His command is pretty good, his mound presence is outstanding. His breaking ball (is good), he has a plus changeup."
Joining recent call-ups Brett Jackson and Josh Vitters, Raley will be the 14th rookie the Cubs have used this season. While Chicago's clearly started to look toward the future, its lack of experience has proven costly during the losing streak.
The Cubs, who've been outscored 31-12 and hit .173 during the skid, saw their woes continue in Monday's series opener. Chicago had four singles among its five hits and went 0 for 4 with runners in scoring position during a 2-0 loss. Jackson, Vitters and fellow rookie Anthony Rizzo each went 0 for 4.
"A tough day for the kids," Sveum said. "That's what they're here for, to see this kind of pitching and make those adjustments."
Acquired from San Diego (47-64) during the offseason, Rizzo is mired in a 4-for-25 slump. Starlin Castro has also struggled of late, going hitless in his last 15 at-bats.
Rizzo and Castro will try to pick up the pace against Padres starter Ross Ohlendorf (3-2, 6.27 ERA), who was knocked around Thursday in a 9-4 loss at Cincinnati. The right-hander was tagged for a season-high six runs, six hits and issued three walks before being removed with two outs in the second inning.
Ohlendorf could benefit from a return home, where he's 1-0 with a 2.13 ERA over two starts. He is 1-0 with a 3.00 ERA in five career matchups versus the Cubs, yielding one run over 14 innings in two outings outside of Wrigley Field.
Despite a 2-for-10 effort Monday, San Diego is batting .325 with runners in scoring position during an 8-2 stretch at Petco Park.