CHICAGO — The Cubs’ struggles at the plate have raised frustration around Wrigley Field.

Kyle Tucker, the superstar slugger the Cubs paid a hefty price for in an offseason trade with the Houston Astros, was booed in Monday’s series opener against the Milwaukee Brewers and will subsequently have a few days off as he works through his struggles.

Seiya Suzuki, Michael Busch and Pete Crow-Armstrong, the other three pillars of the lineup in the first half, have struggled after the Midsummer Classic. The offense that seemingly put up crooked numbers on the scoreboard every day has squandered prime scoring positions multiple times over the last several weeks.

“We play every day for six months and there’s going to be, even with a really good team, you have really good stretches and you’re going to have some stretches where you’re grinding,” Cubs president of baseball operations Jed Hoyer said before Monday’s 7-0 loss to the Milwaukee Brewers. “And we have been now for a bit offensively.”

So, how do the Cubs snap out of it? Why not sit Suzuki or left fielder Ian Happ, whose .714 OPS would be the lowest in a season in his nine years in the big leagues, for top prospect Owen Caissie, who was brought up after tearing the cover off the ball in the minors?

“You have three really good players that would be playing ahead of him,” Hoyer said, referencing Suzuki, Happ and Tucker. “He’s going to get some at-bats, but certainly, in order to play every day, it’s really sitting down a veteran player who’s a really good player who projects really well. So I think that’s the reason.”

OK, so why not change up the lineup that’s remained largely unchanged since Busch slotted into the leadoff spot at the end of July?

“I’m going to give an answer that will frustrate people, but hit your best players at the top of the lineup,” Hoyer said. “Hit them the most often. I was taught that 25 years ago by Bill James when we’re talking about lineup construction. I think you want to avoid clusters of handedness to make it easy on the opponent.

“Hit your best players the most often is really simple, and it works. And you got to do that.”

OK, fair enough, but then why not throw Matt Shaw, who has a 1.018 OPS with eight homers and 17 RBI since the All-Star break, higher in the lineup while that quartet of hitters try to regain their mojo? He is your best hitter right now, after all.

“I think we all talk about lineup construction and those different things, but the idea that ‘Hey, this guy’s hitting well and batting eighth, I’m now going to bat him second,’ you don’t really know if that guy is about to start a cold streak or not, right?” Hoyer said. “So generally, we have a lot of analytics, we have a lot of projection systems, and in general, just fall back on you hit your best players most often and avoid clusters of handedness to make it easy on the opponent, is sort of the simplest way to go about it.”

In other words, the larger sample of success from Tucker, Busch, Suzuki and Crow-Armstrong means the Cubs want those guys taking the lion’s share of the at-bats. Shaw, who has a .682 OPS overall in his rookie campaign, doesn’t have the track record of success of those other four.

That makes sense. But since the Cubs’ offensive woes have coincided with Happ’s removal from the leadoff spot and Busch’s ascension to that role, why not revert to the lineups from earlier in the season when the left fielder was hitting first and the first baseman was hitting around the No. 4 spot?

“I think that no question you try to mix things up,” Hoyer said. “There’s a psychological component, and we’ve done that a few different times, but we weren’t scoring the most runs in baseball because Ian Happ was leading off.

“He was leading off when we were scoring the most runs in baseball. And I think that’s just an important thing to remember. It’s not the order in which they hit, it’s how they’re hitting.”

And that’s ultimately the root of the Cubs’ woes. The boppers aren’t mashing. The offense that averaged 5.33 runs per game in the first half (the second-most in baseball) is scoring just 3.64 runs a game since the break, the second-fewest in the game.

“What I’m really saying is I just think that the answers to our struggles are not lineup construction,” Hoyer said. “I think sometimes you can simplify it down to, our best players haven’t been producing at the level they were in the first half.

“That’s the reason that we’re not scoring as many runs. It’s not the order in which they go to the plate.”