On Sept. 15, 2014, they knew it for sure.
Correa's 2014 season had ended in June, when he fractured the fibula above his right ankle. After having arthroscopic surgery, he left his Class A team in Lancaster, California, just an hour northeast of Los Angeles, to begin his rehabilitation under the supervision of the Astros' training staff at the club's facility in Kissimmee, Florida.
Fast forward to September, and Lancaster was playing for the California League championship -- its best-of-five series against the Visalia Rawhide (an Arizona Diamondbacks affiliate) that was knotted at two games apiece. And Correa couldn't bear the thought of following along by staring at a computer screen some 2,500 miles away, just refreshing the score over and over again.
"I got hurt and my season got cut short, but I still felt like I was part of the team," Correa recalled recently. "I just felt like I should've been there."
And so Correa dipped into his $4.8 million signing bonus and flew across the country. He arrived at Lancaster Municipal Stadium -- or "The Hangar," as it's called -- shortly before the first pitch of Game 5 and surprised his teammates with a pregame pep talk before a 10-2 victory.
"The first thing he asked me, he's like, 'Hey, can I sit in the dugout?' I told him, 'You can be my bench coach,'" said Rodney Linares, Lancaster's manager in 2014. "And he had a really good speech. It wasn't like, 'Let's go! Rah-rah!' He just said, 'Everything we did for the entire year sums up to this.' When he showed up, it showed me a lot."
Actually, it left many Astros officials flabbergasted.
Winning and losing are rarely emphasized in the minor leagues, with the development of individuals taking priority. The best teams at the beginning of a season are often weakened by the end, the result of mass promotions to the next level. Most minor leaguers can't wait for the season to end in the hopes of receiving a September call-up to the majors, or a well-earned break before heading to the Arizona Fall League or winter ball.
Yet there was Correa, still a week shy of his 20th birthday, caring enough about teammates he hadn't seen since late June of that year to make sure he was by their side. If the Astros didn't already think they had a future superstar in their midst -- a cleanup-hitting shortstop who could help lead them to an American League pennant and the second World Series appearance in franchise history -- they did after that.
"I don't know if you see that from a guy who signs No. 1 overall, 19 years old, but he's always been very caring of his teammates and trying to fight for the guy next to him," said Astros pitcher Lance McCullers Jr., a member of that Lancaster team. "He was super-close to a lot of the guys on that team, including myself, and we were asking him, 'Please come back. Please come back. We want you here to experience this with us.' It raised everyone's spirits to see him again."
Said former Astros scout Paul Ricciarini: "That meant more to me than watching him hit home runs and make great plays. He told those guys, 'We worked hard all year. I want that damn ring.' How many kids are going to do that, especially with his talent? You just don't find kids like that. Learning that about him and watching the passion and the honesty that he had for his teammates, that's a Hall of Fame makeup."
Looking back, though, Linares says it wasn't out of character for Correa, who often showed maturity beyond his years as he zoomed through the Astros' farm system.
Take, for example, when he showed up to spring training in 2014. The Hangar is known as a hitters' paradise because of the gusty winds that tend to blow toward the outfield. It isn't unusual for home run totals to be inflated at that park, and with Correa ticketed to open the season in Lancaster, expectations were that the 6-foot-4, 215-pounder would routinely test The Hangar's limits.
But Correa had other ideas.
"Everybody knows Lancaster is a launching pad, right?" Linares said. "Well, we get there and he says, 'Jefe,' -- he called me 'Jefe' -- he goes, 'The only thing I'm going to tell you is don't worry about Correa and homers because all I want to do is learn how to hit the inside fastball and get my defense better.' He goes out there and he's hitting .330 or whatever, but he hasn't hit a lot of homers. Everybody's like, 'What the heck is going on? This guy is a power guy. Why's he got six homers and everybody else has got 20?' But he had a plan. He knew what he wanted to do to make himself a better hitter."
"He's a once-in-a-generation type player ... you don't get those guys off the street."
The following spring, after his leg injury healed, Correa went to Double-A (the Corpus Christi Hooks) and played in a preseason exhibition game against the Astros. Before the game, he popped into Linares' office for a word.
"Hey, remember what I told you last year?" Correa said. "Well, I learned to hit the inside fastball. Now, watch me take off."
Sure enough, Correa homered against Astros reliever Josh Fields, the precursor to seven homers in 117 Double-A at-bats in a meteoric 2015 season. He got promoted to the big leagues in June of that year, hit 22 homers in 387 at-bats and was crowned American League Rookie of the Year.
"Every day that we played, every game that we played, he did something that would wow you," Linares said. "Makeup-wise, probably Carlos is the best I've ever been around. He's a once-in-a-generation type player. Those guys, you don't get those guys off the street."
If Correa took a small step backward last season -- his home run total dipped from 22 to 20 and his OPS from .857 to .811 -- he surged back to the top of baseball's young shortstop class this year. Despite missing 42 games in July and August because of a torn ligament in his left thumb, Correa batted .315 with 25 doubles, 24 homers and 84 RBIs. He reached base at a .391 clip and posted a .941 OPS, MVP-worthy numbers if he hadn't gotten injured.
True to form, Correa doesn't believe he's a finished product. As much as any of the young Astros, he has watched and learned from 40-year-old designated hitter Carlos Beltran, a fellow native of Puerto Rico whom Correa says has "taught us so much about the game, things that we didn't know about."
"He's so smart, he's so passionate about the game," Beltran said. "He doesn't want to be good; he wants to be great. And when I see that in a younger guy, I'm motivated to help him and to share information that has been key for me in my career. And he's a good learner, man. It's not difficult to teach a guy like that. I'm proud of how he's been able to handle every situation."
Even flying across the country to root on Single-A teammates in a championship game that few outside of Lancaster would remember.
"The guys all went crazy. They started jumping all over me, and I was like, 'Easy, easy. My ankle's still not ready,'" Correa said. "But to me, it meant everything to be there just because I spent a whole season with that group of guys. I saw them more than I saw my family, so they became family. It was one of the best moments of my minor league career, for sure."
It was also the moment the Astros knew Correa's character matched his talent.