DENVER -- Pete Crow-Armstrong hopped to his feet and gave a quick shake of his glove. The rookie center fielder then nonchalantly flipped the baseball he just snagged up into the air, catching it with his bare hand as the crowd buzzed. On the mound, Cubs reliever Daniel Palencia hoisted both arms skyward.

“I expect to make those plays,” Crow-Armstrong said.

And that is why the Cubs plucked the kid they call PCA from the farm and tossed him into the thick of a playoff chase. Chicago wanted to add his elite defense to the equation as the ballclub pushed for October. Crow-Armstrong could not stop a 6-4 loss to the Rockies on Tuesday, but he did drop jaws in the first start of his MLB career.

• Games remaining: at COL (1), at AZ (3), vs. PIT (3), vs. COL (3), at ATL (3), at MIL (3).
• Standings update: The Cubs (78-68) are four games behind the Brewers (81-63) for first place in the NL Central. The Cubs and Brewers have split the season series so far, so the tiebreaker has not yet been determined. Chicago sits in the second Wild Card spot, trailing the Phillies (79-66) by 1 1/2 games, and holding a two-game lead over the third-seeded D-backs (76-70). The Marlins, Reds and Giants are also in the hunt. The Cubs have won the tiebreaker over San Francisco, but lost it to Philadelphia, Cincinnati and Miami. They have gone 1-4 against Arizona with three games left in the season series.

Twice in the defeat, Crow-Armstrong showed why some evaluators believe he is already one of the top center fielders in the game. Nolan Jones just happened to be on the wrong end of the pair of impressive catches by the Cubs’ top prospect, and Pipeline’s No. 12-ranked prospect in all of baseball.

“I’ve seen a lot of highlights of that kid out in center field when he was in the Minors,” said Rockies center fielder Brenton Doyle, who leads the National League with 13 Defensive Runs Saved at the position. “After this series, I’ll be excited to watch him play even more.”

In the first inning, Jones crushed a pitch from Cubs righty Javier Assad to deep center field. The 21-year-old Crow-Armstrong was off to the races, sprinting to his right to chase down the ball before it could find the warning track.

Crow-Armstrong left his feet briefly and snared the ball from the air, slamming into the padded wall with his hat popping off. That revealed his thick mop of red hair, bringing life to the expression “playing with his hair on fire.” The ball Jones hit had an expected batting average of .970, according to Statcast.

“He's a great outfielder,” Assad said via team translator Fredy Quevedo. “He's a very, very talented individual that covers a lot of ground. That was great.”

As Crow-Armstrong quickly fired the ball back to the infield, the heavily Cubs-leaning crowd at Coors Field joined together in a “P-C-A!” chant. For Chicago’s fans in Denver, it was the first in-person look at what should be the first in a long line of highlight-reel plays for the center fielder in the big leagues.

“Pete played his tail off in center,” Cubs manager David Ross said. “He made some really great plays.”

Crow-Armstrong also had both his parents – Ashley Crow and Matthew John Armstrong -- plus a group of long-time friends, in the stands cheering him on. The center fielder’s dad made it to Tuesday’s game after Crow-Armstrong made his MLB debut on Monday night.

“He's a Cubs fan through and through,” Crow-Armstrong said. “He's the one that got me into my baseball fandom. And it's nice having him here. He didn't get to be here last night, but I was kind of giving them some guff for that.”

All of Crow-Armstrong's fans did not have to wait much longer for the next great catch

This time, Jones ripped a low slider from Palencia deep into the right-center-field gap in the sixth inning. According to Statcast, this ball had a catch probability of just 15 percent.

Crow-Armstrong bolted to his left, hitting an elite sprint speed of 30.7 feet/sec. as he flew across the spacious Coors Field outfield. He dropped into a slide, extending his glove hand and making a back-handed grab at the final moment.

“He makes my life easy out there,” quipped Cubs right fielder Seiya Suzuki, via his interpreter, Toy Matsushita.

“I have dreamed about -- literally dreamed about -- making those catches,” Crow-Armstrong said, “and tried to picture what it'd feel like. I'd say that it exceeds what I thought. But that's just the preparation I've done and the work I've put in.”

There was just one thing missing from PCA’s impressive night.

“I'm having a hard time getting past the loss,” said Crow-Armstrong, who went 0-for-4 with one RBI. “I'll make those plays every chance I get, but I also want to produce every chance I get.”