Five days before his first start of the 2019 season, Cubs pitcher Kyle Hendricks signed a four-year, $55.5 million contract extension.

Then, he blinked.

Before a guy team president Theo Epstein had just called “one of the half-dozen most effective pitchers in the game” knew what hit him, he was 0-3.

In his fifth and final start of April, Hendricks got lit up by the Diamondbacks for seven earned runs — the first time in his career he’d given up that many — to fall to 1-4 with a 5.33 ERA.

“Not good,” he said at the time.

If only his pitching had been as spot-on as his analysis.

But Hendricks roared back to life in his very next start, which, in light of Epstein’s words, shouldn’t have surprised anyone. Against the Cardinals at Wrigley Field, he went the distance in only 81 pitches — the fewest in the major leagues in a nine-inning complete game since the 2012 season and the fewest by a Cub in a nine-inning complete game since Jon Lieber’s 78-pitch masterpiece in 2001.

It was the beginning of an eight-start stretch during which Hendricks was as good as he’d ever been, going 6-0 with a 1.99 ERA and gobbling up 58⅔ innings.

It was a clinic in commanding his pitches, the strike zone, the hitters, the umpires, the peanut vendors and everything and everyone else.

It was a master class in nerding out on the mound, or whatever one should call the zone “the Professor” goes into when his arm and mind are in perfect alignment.

The stretch ended with a thud as Hendricks finally lost a game and promptly went on the disabled list with inflammation in his shoulder. He would miss a couple of turns in the rotation and go more than seven weeks between victories. The final tally for 2019 would include an 11-10 record and a 3.46 ERA in 30 starts — not bad.

But that stretch was a reminder of what Hendricks can be, and of what he can — and must — mean to the Cubs if they’re going to contend again while he and fellow starter Yu Darvish are under contract through at least 2023.

We sure talk a lot about Darvish around these parts when baseball is happening, don’t we? And when we’re not obsessing over Darvish, we fixate on Kris Bryant. Or Javy Baez. Or Anthony Rizzo, Kyle Schwarber, Willson Contreras, Jon Lester or an ever-changing bullpen.

Somehow — perhaps because he’s so mild-mannered — Hendricks, 30, lives under the radar by comparison. It’s a poor measurement of his importance to the team’s present and future.

“Don’t overlook Hendricks,” Lester said during spring training. “Anyone who doesn’t think Kyle could be [our] ace, I don’t know what they’re thinking. He’s a great pitcher. He has probably been our best pitcher for a while now.”

Hendricks was much more than met the eye as a rookie in 2014, going 7-2 with a 2.46 ERA as a last-place team went 11-2 in his starts. He finished third in National League Cy Young voting in 2016, when he led the majors with a 2.13 ERA. He was locked in again over his last 12 starts in 2018, going 8-2 with a 2.51 ERA.

In Mesa, Arizona, before the coronavirus outbreak put the season on hold, new manager David Ross described Hendricks’ early-spring work as “phenomenal.” Ross sensed a big year coming for the right-hander, and Hendricks sensed it, too.

Whenever baseball gets going again, Hendricks will have as much say in the Cubs’ success or failure as anyone. Lester is down to his last bag of bullets. Darvish is a walking question mark. Hendricks is still in the thick of his prime.

What he has done so far has been awfully good. Maybe what’s left is even better?

As things wrapped up last season, Hendricks — perhaps not bound for the broadcast booth post-retirement — addressed that question in three simple words:

“That’s the plan.”

And a fine one at that.