CHICAGO -- For the second time at Wrigley Field this year, the Cardinals were handed a series sweep by the rival Cubs.

Dropping Sunday night's series finale, 5-1, St. Louis fell below .500 (31-32) and 5 1/2 games back of the Cubs and Brewers, who are tied atop the National League Central.

• Box score

Here are three takeaways from the Cardinals' 0-3 weekend in Chicago:

The rotation stumbles
Cardinal starters -- Miles Mikolas, Jack Flaherty and Adam Wainwright -- combined for just 12 innings this weekend. Mikolas (right forearm contusion) and Wainwright (left hamstring tightness) both exited early with injuries. While Mikolas won't miss a beat, Wainwright will likely miss at least one start.

Which means that the Cardinals now have two starting spots up in the air. More will be determined on Wainwright's timeline to return, but the Cardinals will likely have to call up a Minor League pitcher for his next turn, Friday against the Mets in New York.

Michael Wacha makes his return to the rotation Monday, and even though manager Mike Shildt said he hopes Wacha will show his elite stuff, Wacha's stay will depend on performance.

Flaherty only made it through 3 2/3 innings in Saturday's 9-4 loss. He walked three and struck out zero -- uncharacteristic for the right-hander, who averages more than five strikeouts per start. Over the weekend, Cardinals starters issued seven walks in those 12 innings.

"It's been too big of a consistent theme as far of the proverbial shutdown inning and the walks," Shildt said Saturday. "That's the thing that bothers me the most. You get hits, you get hit, you don't have your stuff, that's going to happen. But we need to be in the strike zone. We need to be on the plate more."

Compare that to the Cubs' rotation -- eight scoreless innings from Cole Hamels on Friday, a six-inning outing from Jon Lester for the win on Saturday and seven innings from Kyle Hendricks on Sunday. The Cardinals mustered eight hits off Hendricks but scored just once, in the second inning.

The offense disappears
The Cubs edged the Cardinals in hits, 25-18, over the weekend, but outscored them, 17-6. Even with nine hits on Sunday, the Cards left nine on base and were 3-for-10 with runners in scoring position.

With the offense on a downturn, are the Cardinals trying to do too much with their aggressiveness at the plate?

Shildt said that's one reason.

"It's a combination of the opposing pitcher making a pitch, it's a combination of us putting a swing on it and not getting enough," Shildt said. "It's part of trying to do too much. That's probably one of the bigger ones, if I could pinpoint it. There's something to be said for caring too much. And wanting it too badly."

Shortstop Paul DeJong said part of the problem is not being able to get anything done in the middle innings. Either they were too late in scoring -- DeJong hit a solo homer in the ninth on Friday -- or they started hot and couldn't finish, with a four-run first inning on Saturday and scoring in the second inning Sunday.

"We were just missing that last bit of energy, that toughness to get over the hump," DeJong said. "We want to beat these guys. They're a good team in our division, and we have our work cut out for us. We're going to step up to the challenge."

The Cardinals can't find a win at Wrigley
For the first time since the Cardinals and Cubs began play in 1892, the home team has won each of the first nine games to begin the season series. The Cardinals have gotten swept the last two times at Wrigley, while the Cubs were swept at Busch Stadium at the beginning of the month.

"It doesn't make sense," Wainwright said. "If you look at the Central as a whole, five very even teams. There's going to be some bloodbaths all year long. But at the same time, we should be at the top of this division. And we're not. There's no excuses for it, we just have to play better."

The Cardinals have a break from the surging Cubs until the end of July at Busch Stadium, and the teams play at Wrigley once more in September. Their last series is in St. Louis, Sept. 27-29.

Could the "winless at Wrigley" trend become a habit? That's what the Cardinals are fighting.

"Keeping that negativity out and being able to separate the games from each other," DeJong said. "We can choose two paths. We can keep fighting and try to keep pushing forward, or we can fall into the 'here we go again' type mentality. I think it's up to each of us individually to come every day and be prepared to win."