CHICAGO -- Starlin Castro's debut in May remains one of the few indelible moments of a typically Cubbish season.
You don't see a 20-year-old kid introduce himself to the majors with a three-run homer and a three-run triple very often. Or ever.
While Castro's unreal entrée was short-lived and he couldn't immediately spark the Cubs into relevance -- he's a shortstop, not a miracle worker -- he has improved as the season has gone on, maturing from phenom to mainstay.
And even though Chicago has struggled to make a run at .500, Castro has made believers out of the most skeptical Cubs fans previously burned by the likes of Corey Patterson, Felix Pie and Hee Seop Choi.
At the plate and on the field, Castro is the real deal, and he's not alone. Castro and fellow rookie Tyler Colvin are two reasons to tune in to Cubs games, and their teammates aren't so shabby themselves.
With a 4-3 extra-innings loss Sunday night, the Cubs, who had a great chance to win in the 10th, failed to sweep the first-place Cardinals out of Wrigley Field, but wrapped up a 6-4 homestand. Chicago heads to Houston 10 games back in the Central. I certainly wouldn't say the Cubs are lurking in the weeds, but maybe they've got the high-powered binoculars out.
Since moving Colvin and Castro to a "daily double" position atop the lineup, the Cubs are 4-3. When Castro hits second, his natural spot in the order, the Cubs are 12-6, a far cry from their 45-54 record.
While Colvin had a rough day, striking out three times and getting caught stealing second in the first inning, Castro had a two-out RBI single that gave the Cubs a brief 3-2 lead and had several nice defensive plays.
While we wait to see if the Cubs are going to unload future free agents in Derrek Lee and Ted Lilly, not to mention any excess veterans GM Jim Hendry can pawn off, it's (seriously) not too late for the Cubs to make an improbable run in the last two months of the season.
I'm no optimist when it comes to the Cubs, but if something improbable does happen, it's clear that Castro and Colvin are providing a spark that has been missing the past two seasons. And given the money the Cubs have thrown at free agents, the two rookies are doing it at bargain prices.
Both have talent, and while both are respectful players, they have that necessary swagger, too.
Colvin made no secret of his desire to play every day when he was sharing time in the outfield, though he didn't cause a stir. Castro has played in all but one game since his debut, starting 43 in a row at one point.
At one point Sunday afternoon in a busy Cubs clubhouse, Castro put on his sunglasses, put his foot up on a chair, with his bat in hand, and looked into the distance. It was a nice pose.
"Now that would make a good picture," a reporter said, before someone dropped the inevitable "his future's so bright he's gotta wear shades" line.
Oneri Fleita, the godfather of the Cubs' minor league system, walked by and stopped at Castro's locker for a few minutes. Castro, a relatively cheap signing four years ago out of the Dominican Republic, is a major coup for the club's farm system.
As is Colvin, who made the leap from prospect to major leaguer in part by sticking to an intensive weight training program this past winter at the team's Arizona complex. A lanky kid, he has added some natural-looking muscle and it's showed at the plate.
Hours before the game, Colvin was caught by the ESPN Sunday Night crew with a plate of hot turkey en route to the players-only lounge. With the plate of food in his hand, he chatted amiably, giving the broadcasters some background information. One thing they asked was if he had ever hit leadoff before this year.
"No, never," said the strapping 2006 first-round pick. "Not once before this spring."
No one is asking if either rookie is ready anymore.
"They're good-looking young kids," Lou Piniella said.
He's not lying. Both completely skipped Triple-A. While Castro shot through the system last year, Colvin wasn't expected to make the team out of spring training, which he did by hitting everything he saw.
"He wasn't given anything," Cubs assistant general manager Randy Bush said. "He came to camp, and every projection we had he was ticketed to go back to the minor leagues for a little more seasoning. He just came out there and demanded to be given a spot the way he played."
Castro, who took shortstop from the defensively limited Ryan Theriot, actually looks about 15. He has mostly conversed with media gaggles through first base coach Ivan DeJesus, though his English is pretty good.
On Sunday, when I approached Castro watching TV, he started talking immediately, another sign that he's a rookie.
"I feel better hitting," he said. "It's better hitting second than batting eighth. The pitchers give you better pitches to hit. Hitting eighth, they throw too much off-speed pitches."
And, he said, when you have Lee and Aramis Ramirez hitting behind you, well, that helps, too.
Castro, hitting .307 overall, had walked only once in the 2-spot, and struck out just six times.
While he was fine in the 8-spot, where he hit .313 (30-for-96), he struck out 20 times and walked 17. Castro's got speed, so a walk's good, but he also has pop in his bat.
"It's a nice position for a young kid to hit in," Piniella said. "The 2-hole's always a good position. You've got the meat of your lineup coming up and if they get behind you, they're going to give you something to hit. But you've still got to be able to handle the bat, and he's done that."
After a sluggish June (.227 batting average), Castro has rebounded with a scorching July (.389 coming into Sunday), with eight multihit games since July 10. His average has gone up almost 40 points in that span. He's driving in runs too. Castro has 31 RBIs overall, and has collected RBIs in five of his past six games. (By comparison, Theriot has 20 RBIs in 134 more at-bats.)
"He trusts himself," said Carlos Marmol, who is close to his fellow Dominican and has seen him develop over the last few years. "When you trust yourself, good things can happen."
While Castro seems to be a good fit in the 2-hole for the near future, Colvin won't be a leadoff man for too long. For one thing, he doesn't walk enough (17 walks and a .321 on-base percentage before Sunday), but mostly, he's got too much power.
Colvin, who has started in only about half the Cubs' games, is hitting .262 and leads all rookies with 15 home runs and came into Sunday's game averaging a homer every 14.4 at-bats. If he kept up that pace through the requisite number of games to qualify to be a league leader, he would be second in the National League.
He's hitting .292 with five homers in 43 at-bats in the leadoff spot, including first-inning homers in the first two games of this series. He singled off Chris Carpenter in his first at-bat Sunday, but was caught stealing second. He grounded into a fielder's choice in the 10th and was stranded at third.
"I don't think anybody projects him to hit there long term," Bush said. "It's good for him right now. He's in a spot where he gets a lot of fastballs to hit. As a young player you like that."
As you can expect, the Cubs are over the moon, or at least the Toyota sign, over these two young, cheap hitters. Typically, this organization pays for hitters and develops pitchers. Perhaps a sea change is underway.
"We're very pleased," Bush said. "I was talking to [hitting coach] Rudy Jaramillo about it today, they're both extremely hard workers. They listen, they try to apply things and they learn from their mistakes."
After Colvin extricated himself from the Sunday Night crew, he made his way to his locker with his ever-cooling food in tow. A reporter asked him if he's going to start talking in the third person if he keeps hitting leadoff homers, a la Rickey Henderson.
"Not at all," Colvin said, pausing a beat and smiling. "Tyler doesn't do that."
Jon Greenberg is a columnist for ESPNChicago.com. You can follow him on Twitter at twitter.com/espnchijon.