Michael Thomas/Associated Press

Yu Darvish was supposed to put the Chicago Cubs on an L train straight to championship city. That was the plan when they signed the right-hander to a six-year, $126 million pact this winter and waved goodbye to free-agent hurlers Jake Arrieta and John Lackey.

A bumpy month-plus into the 2018 season, it's worth asking: Will Darvish derail the Cubbies' title trip?

Yes, we're in small-sample territory. Entering play Monday, Darvish has made six starts in a Cubs uniform. The results, however, haven't been pretty.

Darvish's ERA is 6.00. He's lasted beyond the fifth inning only twice and hasn't thrown more than six innings in any of his outings.

Now Darvish has strangely hit the DL because of the flu, and it has caused more negative attention thrown his way—fairly or not.

Doubting his illness is silly, but those already frustrated with early returns are flocking to social media to question his toughness. Go ahead and search "Yu Darvish flu" on Twitter. I'll wait.

Even more troublingly, he's clashed with catcher Willson Contreras.

After Darvish surrendered five earned runs in 4.2 innings to the Colorado Rockies on April 21, Contreras took the right-hander to task.

"It looks like he got too comfortable when he got the second out [in the fifth inning]," Contreras said, per Rick Morrissey of the Chicago Sun-Times. "In the big leagues, no matter how many outs there are, you have to keep attacking the hitters. I hope we learn from that."

Michael Thomas/Associated Press

Darvish is a decorated MLB veteran with four All-Star appearances and two top-10 Cy Young Award finishes under his belt. Contreras is 25 years old and caught a career-high 108 games in 2017.

The Cubs, though, seem to be siding with Contreras.

"In two games, everyone thought it was a nice combo," Cubs skipper Joe Maddon said, per Mark Gonzales of the Chicago Tribune. "And Yu had a tough time, and all of a sudden, it's the catcher's fault.

"It has nothing to do with the catcher. Can y'all write that down?"

If Darvish's struggles aren't about his backstop, what are they about? And will they undermine the Cubs' quest for a second Commissioner's Trophy in three years?

To the first question, there are positive signs. Darvish's numbers are ugly, but his average fastball velocity of 94.9 is above his career mark of 94.1, per FanGraphs. In between his struggles, he's missed bats, with 37 strikeouts in 30 innings. His 4.10 xFIP, while not stellar, suggests a degree of bad luck.

"He has a strong mental skill set, but like most pitchers, like most players, it's not perfect," Cubs president of baseball operations Theo Epstein said, per Steve Rosenbloom of the Tribune. "It's not fully formed. It's not instantly transferable to a new set of circumstances and a new environment and new challenges and a new coaching staff and new scouting reports and a new way of doing things and new expectations."

Here's the part where we must exhume Darvish's World Series face-plant.

After going from the Texas Rangers to the Los Angeles Dodgers in a 2017 trade-deadline swap, Darvish laid an egg in the Fall Classic.

In his first World Series start, in Game 3 at Minute Maid Park, he lasted 1.2 innings against the Houston Astros and surrendered six hits and four earned runs. The Dodgers lost, 5-3. In the pivotal Game 7, he coughed up five runs (four earned) in 1.2 frames as L.A. fell again, 5-1.

Two starts, two high-profile duds. It doesn't erase Darvish's exemplary MLB career, but it's worth an eyebrow raise at least.

Suppose his mediocre results continue. Could the Cubs bathe in Champagne and confetti in spite of, rather than because of, their shiny offseason acquisition?

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The Cubs (16-14) are looking up at the St. Louis Cardinals (19-12) and Milwaukee Brewers (20-15) in the National League Central. Other challengers lurk, including the Dodgers and Arizona Diamondbacks out West and an array of contenders in the surprisingly deep East.

The offense has done its part. Chicago ranks fifth in the Senior Circuit in runs scored and fourth in OPS. An enviably deep lineup led by Kris Bryant, Javier Baez, Kyle Schwarber et al. will do its part. The Cubs bullpen ranks third in baseball with a 2.78 ERA.

As for the rotation? Jon Lester (2.73 ERA) and Kyle Hendricks (3.19 ERA) represent a solid one-two punch. Tyler Chatwood has struck out 32 in 32.2 innings. Jose Quintana sports a 4.99 ERA, but the Cubs have won four of his six starts.

Chicago wants Darvish to pitch like the guy who picked up stray MVP votes with the Rangers in 2013. The Cubs paid him like an ace, and they have every right to expect ace-level output. But if Darvish can simply live up to his xFIP and be a consistent mid-rotation performer, Chicago will be all right.

He's earning $25 million this season, however. He'll make another $20 million in 2019. After that, he can opt out or settle in for another $81 million through 2023, his age-36 campaign.

Long-term, the Cubs need Darvish to be better than a 6.00 ERA pitcher. A lot better. Short-term, a modicum of patience is warranted.

Buyer's remorse aside, the train isn't off the tracks just yet.

All statistics and contract information accurate as of Sunday and courtesy of FanGraphs and Baseball Reference.