Luck (calf) attended practice Sunday on the sidelines wearing a red jersey, Zak Keefer of The Athletic reports.

EDGE Analysis

Luck didn't travel with the Colts to their preseason game Thursday and hadn't been seen at most of the nine practices he's missed due to a setback to his calf injury. It's not clear when he may return. While this may be a sign of progress, he'll need to step on the practice field before we can be more confident he'll be ready for the regular season. Luck and the team have said they're confident he'll be ready for Week 1, but Luck also said he is dealing with some pain in his calf after missing all of spring workouts due to the issue.