Luck sustained the injury on a scramble during the first half of Saturday’s 23-17 preseason victory over the San Francisco 49ers.
Colts coach Frank Reich emphasized on Monday that it is not a major injury and that Luck would play this week if it were a regular-season game.
Luck likely would not have played in the Colts’ final preseason game on Thursday against the Cincinnati Bengals even if he was completely healthy. The two teams will meet again in the season opener on Sept. 9.
The 28-year-old Luck, who missed all of last season with a right shoulder injury, threw a touchdown pass in Saturday’s game against the San Francico 49ers.
After starting all 16 games in each of his first three seasons and guiding Indianapolis to identical 11-5 records, Luck was limited to seven starts in 2015. He made 15 starts in 2016, throwing for 4,240 yards and 31 touchdowns versus 13 interceptions.
The Colts finished 4-12 in 2017 with Jacoby Brissett starting 15 games at quarterback. Recurring soreness in Luck’s shoulder prompted the Colts to finally shut him down two weeks after he returned to practice in early October. He was then placed on injured reserve on Nov. 2.