A left shoulder injury suffered against the Lions (Nov. 24) makes it difficult for him to tackle.
Coming into Week 13 Urlacher led the NFL in tackles by one over Miami middle linebacker Zach Thomas. But he matched his season low with 11 tackles against Green Bay, partly because of the shoulder injury.
Obviously, Urlacher's lack of production worries the team, but the true concern is his long-term health.
"That's no different than any other player," coach Dick Jauron said. "It just happens to be a marquee name, but we treat everyone the same in that regard. We would not take a chance with anyone."
The Bears have hesitated in the past to use a starting player in a dual role, so Johnson could be out on punt returns.
Possible replacements include Ahmad Merritt and Adrian Peterson. However, Merritt is already handling kick return duties and has shown some playmaking ability, thus the team would likely give the duties to Merritt.