The Colts have "guarded optimism" regarding Luck's (calf/ankle) ability to be ready for Week 1 against the Chargers in Los Angeles, Chris Mortensen of ESPN reports.

EDGE Analysis

Luck will have to make quick progress with his injury, which initially was termed a strained calf but also involves a high-ankle issue. The reason? Coach Frank Reich wants to make a decision on his starting quarterback for the regular-season opener after the Colts' third preseason game on Aug. 24. Upcoming practices may go a long way to determining whether Luck is on pace for game action on Sept. 8, but the veteran signal-caller hasn't practiced in weeks. If Luck is deemed unable to play Week 1, Reich will turn to Jacoby Brissett under center.