Roach filling the void at linebacker for Bears

ATLANTA - The Bears never intended to be down to their No. 3 middle linebacker by Week Four, but after Brian Urlacher suffered a season-ending fractured wrist and Hunter Hillenmeyer was sidelined with a fractured rib, they turned to Nick Roach. The third-year veteran from Northwestern responded with a team-best 10 tackles against the Lions, and he had a team-high 6 in the first half against the Falcons.

"Ideally you'd like to not have to go to your third middle linebacker, but that's life in the NFL," Bears coach Lovie Smith said. "If you have to, it's good to have a guy like Nick, a smart football player who's been around here for a while and plays hard. Everything we've given him, talking about the different roles, he's performed well: as a special-teams player, of course being our Sam (strongside linebacker) and now at Mike (middle linebacker). The two games he's played, he's played well."

Roach started the season as a backup but took over on the strong side after two plays in the season opener when Pisa Tinoisamoa suffered a sprained knee. Roach moved to the middle when Hillenmeyer was hurt against the Seahawks. At 6-feet-1, 234 pounds, Roach is undersized for the middle, especially when compared to the 6-foot-4, 258-pound Urlacher, but Smith says he's big enough.

"Our guys need to be a little more athletic," Smith said. "That's the model of the guy that's played middle linebacker in our system. The people around here are a little spoiled because we have a special guy in Brian Urlacher. Brian isn't the norm by any means, but if you can't have a Brian, it's good to have a Nick."

Fort Knox: Rookie Johnny Knox's 23-yard TD reception gave him four straight games with a touchdown. In Week Four against the Lions, he scored on a 102-yard kickoff return. In the two previous games, he had 7-yard TD grabs from quarterback Jay Cutler.

Knox, who entered Week Six leading the NFL with a 35.8-yard kickoff-return average, had 1 kickoff return in the first half for 33 yards.

In and out: Nick Roach started at middle linebacker for the second straight game in place of Hunter Hillenmeyer (ribs), who was inactive. Pisa Tinoisamoa started at strongside linebacker for the first time since suffering a sprained knee in the season opener. But he left the game with a knee injury and did not come back.

The Bears' other inactives were wide receiver Juaquin Iglesias, running back Adrian Peterson, cornerback D.J. Moore, guard Lance Louis, defensive tackles Matt Toeaina and Jarron Gilbert and newly acquired defensive end Gaines Adams.

Wide receiver Devin Aromashodu was active for the first time this season.

Odds and ends: Falcons wide receiver Roddy White was coming off a franchise-best 210 receiving yards in Week Five against the 49ers that included 8 catches and 2 touchdowns. He had just 2 catches in the first half against the Bears, but the second was for a 40-yard TD. ... The Bears were 3-2 under Lovie Smith in the week after a bye. ... Bears assistant defensive backs coach Gill Byrd's son, Jairus, a rookie with the Buffalo Bills, had his second interception Sunday.