CHICAGO -- The Cubs were not planning on promoting Nico Hoerner to the big leagues this past season, but circumstances did a number on those plans and Hoerner put on the kind of show down the stretch that might just keep him in the Major Leagues come Opening Day.

Hoerner was home in California in early September -- fresh off the end of his season with Double-A Tennessee -- when an emergency struck and the Cubs broke the glass. With both Javier Báez and Addison Russell out with injuries, the rookie settled into shortstop and more than held his own as he learned to navigate the big leagues on the fly.

"Incredibly impressive feat," Cubs president of baseball operations Theo Epstein said in September. "We can sit here now and say there are X, Y and Z developmental goals that he needs to accomplish in Triple-A, even though he's been in the big leagues for a few weeks. Those can be valid, but they might not apply to him.

"He might have a great offseason and show up and be more than ready. We're not ready to make that decision, but he's a pretty special kid and brings a lot to the table for any team."

The 22-year-old Hoerner, who was taken in the first round (24th overall) of the 2018 MLB Draft out of Stanford, hit .282/.305/.436 with three homers, 13 runs and 17 RBIs in 20 games for the Cubs. That came after he hit .284/.344/.399 in Double-A, where he started 40 games at short, 14 at second and 11 in center field in an injury-shortened season.

Hoerner's time with the Cubs included a red-hot start (.351 average and .968 OPS in his first nine games) and a cold finish (.220 and .531) over 82 overall plate appearances. He tried to keep things simple by not overwhelming himself with data and video out of the gate, and spent time picking the brains of teammates like Ben Zobrist and David Bote.

Along the way, the biggest lesson Hoerner learned was that he feels ready for the Majors.

"It's both getting results," he said, "but also just the feeling in your gut that the same things you've done your whole life well, you still do well. And the same things you need to work on continue to be true. It's a place where, when you do have things you need to work on, they get exposed quickly. But we also have great resources here to work on your game.

"So, there's both sides of it. I think it's been awesome. It's staying present and winning each game and at-bat and pitch, but also developing at the same time. I don't think it's the kind of thing that, just because I'm here, the development stops or anything like that. I've learned more than ever here."

What went right?

Hoerner made it into 14 Cactus League games during Spring Training and immediately made a strong impression. The shortstop hit .471 (8-for-17) with no strikeouts and six extra-base hits with the Major League club in preseason play. Hoerner finished his campaign with Double-A Tennessee strong after injuries threatened to hinder his development. Then, when Chicago needed a shortstop in the thick of a playoff race for the final few weeks, Hoerner stepped in seamlessly and put himself firmly on the map for 2020.

"I think it lets people know that I'm going to do my best regardless of the situation to be consistent and be who I am," Hoerner said in September. "No one's looking at batting average or stats right now. The sample size is too small. It's just playing with composure -- I think that matters. It's just letting people know that I'm ready for what comes my way."

What went wrong?

Hoerner was hit on the left hand by a pitch on April 23 and sustained a hairline fracture of his left wrist. That injury cost him two months on the shelf and took a toll on his production following his return to Double-A Tennessee on July 4. Hoerner hit .232 with a .637 OPS in 25 games in July before starting to look more like himself at the plate in August and September.

Best moment

Neither Hoerner nor Cubs fans will soon forget his historic MLB debut.

On Sept. 9, Hoerner collected four RBIs, three hits (including a triple) and two runs scored in a 10-2 romp over the Padres. Hoerner joined Joey Gallo (2015), Mark Quinn (1999), Ben Grieve (1997) and Bob Nieman (1951) as the only players since at least 1908 to have at least two runs, three hits and four RBIs in their MLB debut. Hoerner and Dee Fondy (1951) are the only Cubs players with at least three hits and four RBIs in their debut with the franchise.

"You could have just put a spotlight on him the entire evening," former Cubs manager Joe Maddon said after Hoerner's debut. "He made some really good plays, had some really good at-bats, ran the bases well. None of that really surprised us. That's what he’s capable of doing."

2020 outlook

Two positions on the field the Cubs need to address this offseason are second base and center field. Offensively, they posted a collective 81 wRC+ at second (19 percent below the MLB average) and an 87 wRC+ in center (13 percent below average). Hoerner spent the bulk of his time at shortstop in September but started at second on Sept. 28 and then in center on Sept. 29. The Cubs wanted to get a look at him at those spots before breaking for the offseason.

Expect Hoerner to compete for a big league job next spring. Assuming Báez is healthy and at shortstop, second base looks like the most natural fit for the rookie. Hoerner is open-minded to whatever the Cubs have planned for him.

"Playing in the middle of the field in the Major Leagues is not a hard sell for me," Hoerner said. "Wherever they need me."