Luck sprained the AC joint in his throwing shoulder while snowboarding in 2016.
Andrew Luck revealed he suffered a shoulder injury while snowboarding in 2016, per the NFL Network's Ian Rapoport.
After tearing his labrum in his right shoulder against Tennessee near the end of the 2015 season, Luck injured that same shoulder early in 2016, spraining his AC joint while snowboarding in Colorado.
"I don't snowboard anymore," Luck told Rapoport. "And this was after the initial injury. I went back, rehabbed it with the Colts. I've had a bunch of AC sprains, both left and right shoulder, and resolved that issue. But the labrum has been my issue, was my issue, what I worked through, what I got surgery on."
Luck contends the sprained AC joint didn't affect his rehab with Indianapolis. He played in 15 games in 2016 before missing the entire 2017 campaign following complications from offseason shoulder surgery.
The former No. 1 pick returned to the field Sunday in the Colts 34–23 loss to the Bengals. Luck went 39–for–53 with 319 yards and two touchdowns.