Correa said by telephone on Sunday that he was "feeling good."
"I'm not worried at all," he said. "I'll be back. I don't know when yet. I know it's nothing really bad."
Speaking on the Astros' pregame show on KBME (790 AM) on Sunday, Luhnow called it "an unfortunate injury."
"Carlos is one of our, obviously, best players in the Minor Leagues, and he just plays the game so hard," Luhnow said. "He slid into third base. He did sustain an ankle injury. We had him evaluated last night, and the next step there is we're bringing him to Houston and he's going to be looked at by our specialist here. We have an excellent ankle and foot specialist that works with us. We'll know more in a couple of days.
"He is going to miss some time. I don't know how long. We have to be very careful with any sort of ankle injury. It's unfortunate. He's had a tremendous season. He's going to miss some time, but the good news is whatever time he misses, he's going to make up for it in the fall. He's probably going to be one of the guys we send to the Arizona Fall League."
Correa, the top pick in the 2012 First-Year Player Draft, was carried off the field after injuring his ankle following an RBI triple in the sixth inning.
"I was worried," Correa said of when the injury first happened, "but it's not as bad. I'll have it checked out in Houston, and they'll be making the final decision."
Correa, 19, who had hit .325 with six homers and 57 RBIs in 62 games at Lancaster, was expected to be promoted to Double-A Corpus Christi soon. He had an on-base percentage of .416 and an OPS of .926, putting him in line to be moved up later this year.
Correa played the entire 2013 season at Class A Quad Cities at 18 years old and was impressive. He hit .320 with 33 doubles, nine homers, 86 RBIs and a .405 on-base percentage. He led the Midwest League in OPS (.872), despite being the second-youngest player in the league, while ranking second in on-base percentage and third in batting average.
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.