Most football people would acknowledge that Brian Urlacher hasn't been the same player this season as he was for most of his career with the Chicago Bears. That makes Tuesday's news of a significant hamstring injury, one that could sideline Urlacher for the rest of the regular season, something short of a catastrophe.

Urlacher has fought gamely through a knee injury that turned out to be more serious than anyone anticipated. He returned to the field in time for Week 1 and established a workable routine of practice time and rest that allowed him to play serviceably for 12 games. But as Matt Williamson of Scouts Inc. noted in an email exchange Tuesday, Urlacher has lost a step. In fact, he probably forced the Bears away from their traditional Tampa 2 scheme and into more single-high safety looks to limit the times he was asked to run downfield.

"By no means is he as explosive or does he move as well as he once did," Williamson said. "He is now a liability in coverage when asked to play Tampa 2, where he has to cover a lot of ground in the deep middle. The Bears are no longer a real heavy Cover 2 team -- and Urlacher's decline probably has something to do with that. I don't think he is a huge loss overall. They will get by."

To me, the scariest part of this injury is that it illustrates the Bears really don't have a backup at Urlacher's position. Tuesday, they re-signed the player who took most of the repetitions at his position in the offseason, Dom DiCicco, but their top option appears to be sliding strong-side linebacker Nick Roach inside and using at Roach's position.

Roach didn't play well as a replacement for Urlacher in 2009, and his status as the No. 2 middle linebacker highlights the risk the Bears took when they didn't seek a viable backup for a player who needed the entire offseason -- and then some -- to recover from a knee injury suffered in early January. It was one of the few clear weaknesses on a roster that general manager Phil Emery worked hard to fortify in multiple areas.

Roach is a veteran with experience and won't embarrass the Bears at the position, but the Bears will weaken two positions to replace one starter. So yes, the Bears defense won't be as good without Urlacher. But that assessment speaks to their depth as much as Urlacher's value at this point.