Veteran Chicago cornerback Kelvin Hayden will miss the entire season after recently tearing his left hamstring in practice at Soldier Field.
Hayden will have surgery to repair the hamstring and will need six to eight months of rehab, Bears coach Marc Trestman said Wednesday. Hayden was injured in practice on Saturday night.
The 30-year-old Hayden has 12 career interceptions.
Second-year player Isaiah Frey will replace him in the nickel back spot in Friday's preseason opener at Carolina. Frey, a sixth-round draft pick out of Nevada, has been one of the surprises of training camp with a handful of forced turnovers.
"It seems like the ball is kind of a magnet towards me right now," Frey said. "I've just got to keep making the plays."
Frey, a practice player last year, has impressed the coaching staff since the start of camp.
"I think Isaiah has got to come out and continue to do what he's doing," Trestman said. "He's certainly in competition right now to be that guy. We've got a long way to go."
Zack Bowman and Sherrick McManus are the experienced reserve Bears cornerbacks behind starters Charles Tillman and Tim Jennings. The Bears had D.J. Moore as an extra nickel back last year, but allowed him to leave in free agency and he signed with the Carolina Panthers.
Hayden, a Chicago native, intercepted Rex Grossman's pass in Super Bowl XLI and returned it for a clinching Indianapolis Colts touchdown in 2007. He becomes a free agent after the 2013 season.
Frey called the 2012 experience he received on the practice squad as invaluable.
"Last year, you come in as a rookie and you don't know really what to expect," he said. "But this year I knew what was going on and was able to be a lot more comfortable."
The injury was one of several to hit the Bears in the past week. Wide receiver Earl Bennett has been sidelined since Saturday with a concussion, which was confirmed by the team.
Bennett also suffered a concussion last December in a loss to the Seattle Seahawks.
Defensive end Julius Peppers has not practiced since Saturday because of a tight hamstring. The Bears are also without starting middle linebacker D.J. Williams (strained right calf) and rookie second-round draft pick Jonathan Bostic will start in his place Friday.
Starting free safety Chris Conte also missed practice Wednesday with hamstring tightness.