ST. LOUIS -- Some two hours prior to their season opener April 7 at Busch Stadium, Cardinals rookie manager Oliver Marmol boldly predicted that the dramatic improvement of his team’s offense would be the overriding storyline of the season.

That afternoon, Marmol looked like a genius, as the Cardinals got home runs from Tyler O’Neill, Tommy Edman and Nolan Arenado, and their offense cranked out nine runs in a throttling of the Pirates.

Since then, however, the Cardinals' offense has largely been a unit that either purrs like a well-oiled machine or more closely resembles a jalopy that wheezes, sputters and belches smoke. In their 17 victories, a Cardinals offense that features the middle-of-the-order punch of Paul Goldschmidt and Arenado, the table-setting prowess of Edman and the veteran savvy of Albert Pujols and Yadier Molina has hammered 28 home runs and it has slashed .239/.313/.376.

Those numbers took an even greater dive Friday when Logan Webb held the Cardinals hitless for four innings, and they mustered just six hits and two runs the rest of the way in an 8-2 loss against the suddenly surging Giants.

“I’m still confident that our offense is going to be a good offense, but right now it’s not,” Marmol said. “We’re in a stretch where certain guys are feeling good about their swings and certain guys aren’t. If we want to talk about inconsistencies from day to day, that’s exactly it. Our job is to get to the point where they feel confident about what they are working on and they can instill that confidence out on the field.”

A lineup that Marmol thought would have more length and depth and one possessing both power and speed has failed to score more than three runs in 16 of 32 games. Paul DeJong has been optioned to Triple-A because of miserable hitting. O’Neill, who was a top-10 finisher in MVP voting last season and someone who jump-started the offense Opening Day with his laser-like home run, has just one round-tripper since April 7 and is in another rut. Only four Cardinals have an OPS greater than .800 -- and two of them are recent rookie call-ups (Juan Yepez and Brendan Donovan).

Adding to the offensive misery: Pinch-hitters have been even worse. That group is still waiting for its first hit after 16 unsuccessful at-bats off the bench.

Overall, the Cardinals’ lows have come nearly as often as their highs, making their offense inexplicably average thus far. They rank 11th in MLB in average (.239), 13th in on-base percentage (.313), 15th in slugging (.376) and 14th in OPS (.689). While they have managed to keep their strikeouts down (236, third fewest in baseball), they have one less home run than the Reds (28).

“We take it day by day -- we’ve had some good games and some not so good, but that’s the way the game goes,” said Goldschmidt, who extended his streak of consecutive games of getting on base to 20 and added a solo home run after the score got out of hand.

On Friday, Webb made the Cardinals look punchless early in the night. By the time the Giants hammered the Cardinals bullpen for five runs in the eighth inning, St. Louis had gotten just one runner to third base.

“The first time through the lineup, I had six out of nine being quality plate appearances with a couple of walks and hit-by-pitches and a line drive by Yepez,” Marmol said. “Second time through, not as much. Some guys stuck with a pretty good game plan, and it paid off. [Goldschmidt] had some good at-bats, but Webb did a nice job. We did a nice job of laying off stuff not in the zone, but not well enough with just three hits and one run [off Webb].”

Asked if a string of stellar starters was behind the Cardinals’ struggles, Marmol interrupted the question and wanted nothing to do with excuses. If the Cardinals are going to accomplish their stated goal of winning a World Series, they must figure out ways to generate offense, the manager said.

“I mean, that’s what you have to beat in order to win a championship,” Marmol said. “Those guys are going to do their jobs, and we have to combat it.”