Hartson was signed after veteran long-snapper
Mannelly was blindsided on Joe Adams' 23-yard punt return midway through the first quarter, but remained in the game through the first half before being replaced by linebacker
Mannelly, 38, holds all-time Bears record with 15 seasons and 231 games played and is the only player from the 1998 draft still active with the team that selected him. He has handled snapping duties in all but nine games during his career, appearing in all 16 games 12 times.
Hartson is an undrafted free agent from Houston who participated in the Bears' rookie minicamp in May on a tryout basis. On his Twitter account Saturday, he wrote: "I'm extremely blessed to be a Chicago Bear. Thanks to my amazing agents and friends." He also changed the profile picture on his Facebook page to a Bears logo.
Hayden needs surgery to repair a torn hamstring he sustained in last Saturday night's Family Fest practice at Soldier Field. The nine-year NFL veteran faces 6-8 months of rehabilitation.
After a day off Saturday, the Bears return to the practice field at 3:15 p.m. Sunday in Bourbonnais.