The team source told Wells that there is "zero truth" to reports that Luck has the partial subluxation.
The injury was discovered during an MRI, according to reports, and is not considered serious enough to keep Luck from playing Thursday night against the Texans in Houston.
The Colts have said Luck is day-to-day. Indianapolis coach Chuck Pagano said Luck threw in practice Tuesday and that he took the majority of the snaps.
The partial subluxation was first reported by Fox 59 in Indianapolis.
According to ESPN's Dr. Mark Adickes, a subluxation is not a dislocation, but it is considered a "lesser version" of a dislocation. In the injury, the ball of the arm bone rides up to the edge of the shoulder socket but does not pop out of the socket, because the surrounding muscles pull it back into place. But the motion of the ball joint can pinch the labrum in the shoulder, causing a bruise on the labrum and some pain and difficulty throwing the ball.
The injury is not the same as a separated shoulder, and Pagano, when asked directly on Monday if Luck had separated his shoulder, said he hadn't heard that.
"Sore shoulder is what I heard," Pagano said.
It is unknown when or how Luck injured his shoulder. Matt Hasselbeck replaced Luck in Sunday's victory over the Jaguars, passing for 282 yards and a touchdown.