Updated

San Diego, CA (SportsNetwork.com) - The San Diego Chargers officially declared two key players out for the season on Sunday, placing both wide receiver Malcom Floyd and outside linebacker Dwight Freeney on injured reserve.

Floyd suffered a sprained neck from a frightening collision during the Chargers' win at Philadelphia in Week 2, while Freeney tore his quadriceps in Sunday's 30-21 victory over Dallas.

Freeney, a seven-time Pro Bowl selection during his tenure with the Indianapolis Colts, who ranks fifth among active players with 108 career sacks, was signed in May after 2012 first-round pick Melvin Ingram tore his ACL during offseason training activities. The 33-year-old had recorded just two tackles and a half-sack over the first four games.

Floyd led the Chargers with 56 catches and 814 receiving yards a year ago and owns a career average of 17.3 yards per reception during his nine seasons in San Diego. The 6-foot-5 veteran had accumulated 149 yards on six catches prior to the injury.

To fill the available roster spots, the Chargers signed wide receiver Lavelle Hawkins and promoted outside linebacker Thomas Keiser from the practice squad.

Hawkins, a former fourth-round choice of Tennessee who was released by both New England and San Diego during the preseason, has compiled 71 catches for 771 yards and one touchdown over a five-year career. His best season came with the Titans in 2011, when the Cal product registered 47 receptions totaling 470 yards.

Keiser amassed 4 1/2 sacks, five tackles for loss and one interception over 14 games with Carolina over the previous two seasons. The 24-year-old originally signed with San Diego in May but was waived during final roster cuts.