More important is Sunday's opposing quarterback, Peyton Manning, who is putting up numbers that would make Dan Marino envious.
If the Bears cannot pressure Manning using just their front four, they run the risk of being carved up like a turkey four days before Thanksgiving. The noon contest at Soldier Field should be the toughest test the Bears' rapidly improving defense has taken this season.
Manning has already thrown 31 touchdown passes, and he's on pace to blow away Marino's NFL single-season record of 48. Manning has thrown just six interceptions. His 122.7 passer rating is the best in the league and would easily surpass Steve Young's all-time NFL record of 112.8. Manning's 2,749 passing yards and his 9.29 yards per pass attempt are also No. 1 in the league. He has thrown nine TD passes in the last two weeks and 14 in the past three weeks.
The Colts lead the NFL in scoring, averaging 33 points per game, and they do it primarily by throwing the ball. They're No. 1 in the NFL in passing yards and average gain per pass play.
"Ideally I'd love to get pressure with only four guys," Bears defensive coordinator Ron Rivera said. "If you don't get pressure on him (with four), then you've got to start doing other things, and they can dictate and they can figure out when you're coming."
Manning does a better job than any quarterback in the league figuring out what defenses are planning to do. That's why he seems to constantly be changing plays and moving players around as he approaches the line of scrimmage. More often than not, he gets the right play called, as evidenced by his gaudy statistics.
But if the Bears continue to get the production they've gotten the past three weeks from their defensive line, Rivera will be able to play his linebackers and defensive backs straight up. That way, they can prevent holes in coverage and not allow the Colts to pile up yards on the ground with Edgerrin James, who is seventh in the NFL with 877 rushing yards.
The most recent performances by the Bears' D-line seem to indicate that it's up to the task. Right end Alex Brown has five sacks in the last two games, left end Adewale Ogunleye has a sack in each of the last two games, and Michael Haynes, who backs up both DE starters, returned an interception 45 yards for a touchdown on Sunday.
Defensive tackle Tommie Harris is a contender for defensive rookie of the year. He's second to Brown in tackles among the defensive linemen and third on the team with 3 1/2 sacks despite drawing double-team blocks that free up teammates to make plays. Right tackle Ian Scott is right behind Harris with 37 tackles and fifth on the team with four tackles for negative yardage.
"Our defensive line gets better and better each week. We think they were dominant most of the time during the course of the game," coach Lovie Smith said after the victory over the Titans. "Our defensive ends have gotten a lot of publicity with how they've played lately, and rightfully so. Alex Brown and Wale Ogunleye both played very well, (and) Tommie Harris, we thought, really dominated the game. He really caused a lot of the things to happen for the ends on the outside. And Michael Haynes had probably the biggest play of the game. We're getting as lot of production from our defensive end position."
Urlacher's absence will make it a more difficult assignment against Manning, but that's expected.
"Playing WITH him, it was going to be difficult," cornerback Jerry Azumah said. "They're a high-powered offense, great running attack, great passing attack and they're really balanced. They don't turn the ball over too much, and they score a lot of touchdowns."
But the Bears defense doesn't allow many TDs. It is No. 9 in points allowed and average gain per pass play and No. 12 in sack percentage.
"We're all making plays, and that's what's good about this team right now," said cornerback Charles Tillman, who hopes to be back on the field Thanksgiving Day against the Cowboys after a nine-week absence.
But the Bears have relied heavily on the defensive line, and they will lean on the big guys up front even more this week.