"In the last week, we only made one error," Maddon said.
On Sunday, the Cubs went 0-for-10 with runners in scoring position. In the last five games, they've gone 4-for-37 with RISP, stranded 44 runners, collected 42 hits, and scored six runs. They're now 11 1/2 games behind the Cardinals in the National League Central.
"You have a young, inexperienced group offensively, and they're being schooled a little bit," Maddon said of his team. "Eventually, it will come back to us. They'll benefit from it. Right now, [the Cardinals] got us -- I get it. I thought we pitched well, played really good defense. We did a lot of things well, we just could not get the hit."
Addison Russell, for example, was 1-for-10 against the Cardinals.
"I have to do a better job of recognizing pitches and laying off pitches out of the zone," Russell said.
He's not alone. Kris Bryant was 2-for-11, while Anthony Rizzo went 1-for-10 in the three-game series.
"As our young guys get more seasoning, we will hit in those situations better," Maddon said.
Sunday's loss meant it was the first time the Cubs have been swept this season. Flashback to 2014, and Chicago had the fifth-worst record in the Majors on June 28 (34-46). Despite this current skid, this year's team is 39-35.
"They kept us in check offensively, which they've done to a lot of different teams," Maddon said of the Cardinals. "We have to get back our offensive mojo."
Carrie Muskat is a reporter for MLB.com. She writes a blog, Muskat Ramblings, and you can follow her on Twitter @CarrieMuskat. This story was not subject to the approval of Major League Baseball or its clubs.