The Cardinals lead Los Angeles by just a half a game in the battle for the second Wild Card spot.
Still, Chambers and his teammates remain upbeat.
"We came from 10 games back last year, so this is no big deal," Chambers said. "We'll get things going."
St. Louis rallied from 10.5 down on Aug. 24 to claim the Wild Card spot in 2011 on the way to its 11th Word Series title.
So this sudden mini-slump is nothing that can't be fixed.
"Tough times do happen," manager Mike Matheny warned. "You've just got to fight through it."
St. Louis has scored just nine runs over 31 innings in losing its last three contests, which is cause for concern.
Right-hander Jake Westbrook struggled for the third time in four outings against the Brewers, who have won 15 of 19.
Westbrook gave up three earned runs on seven hits in a short five-inning stint. He walked four and struck out two. Westbrook allowed 10 of 12 baserunners to reach safely during one stretch in the second and third innings.
"I was pretty shaky early on, it was pretty much a battle all night," Westbrook said. "I made some mistakes that hurt us. [I was] erratic in my mechanics. I was all over the place, fighting it a little bit. That made my location not as good."
Westbrook went at least six innings in 13 successive starts this season, a streak that ended on Aug. 23.
Westbrook has given up 17 earned runs in 20 1/3 innings over his last four starts, none lasting longer than 5 1/3 innings.
In addition to losing their third successive home game, the Cardinals also endured minor injuries to David Freese and Matt Carpenter. Freese suffered an ankle injury and left the game in the eighth inning. Carpenter cut his hands on a broken bat and departed after a base hit in the third. Both are considered day to day by Matheny.
Freese was more upset with his team's recent performance than he was with the injury.
"You can't let this happen this late in the year," he said. "It's crunch time."
Freese will not play Sunday, but says he expects to be back in the lineup Monday when the Cardinals open a seven-game road trip at San Diego.
St. Louis, which faced an uphill battle all night, scored in the seventh and eighth on Saturday to close to within 4-3. Chambers ripped a run-scoring triple in the seventh. Skip Schumaker brought in Yadier Molina with a sacrifice fly in the eighth. Molina led off with a walk and Pete Kozma doubled to put runners on second and third against reliever Jim Henderson with no outs. Henderson rallied to strike out Daniel Descalso. He then got pinch-hitter Carlos Beltran to pop out.
The Cardinals managed just one run on five hits against Mike Fiers, who went five innings. Descalso drove in Freese in the second with a two-out single to right. Freese doubled with one away.
St. Louis loaded the bases in the fifth on a single by Jon Jay and back-to-back walks to Matt Holliday and Allen Craig. But Molina, swinging at the first pitch, flied out to center.
"Another game of missed opportunities offensively," Matheny said. "Much more could have been done on the offensive side."
The Cardinals have stranded 10 runners in each of their last two games and are a combined 3-for-23 with runners in scoring position during that span.
Brewers manager Ron Roenicke says his pitching staff deserves part of the credit for the Cardinals' offensive woes.
"For our pitchers to be able to keep them down in the run total, that really good," he said. "That's why we're winning all these games right now."
Milwaukee scored twice in the second and once in the third to go up, 3-1. Fiers chipped in with an RBI single up the middle on a two-strike offering in the second.
The Brewers pushed the lead to 4-1 in the seventh. Rickie Weeks led off the frame with his 17th homer of the season against Trevor Rosenthal.