In a significant boost for their defense, the Los Angeles Chargers have activated linebacker Khalil Mack and Denzel Perryman from injured reserve. Mack, who has been recovering from a dislocated elbow, is listed as questionable for the upcoming game against the Indianapolis Colts. The Chargers have also placed offensive tackle Joe Alt on the injury report as doubtful for Sunday. The return of these key players comes at a crucial time for the Chargers as they look to strengthen their lineup in Week 7.