Initially, Clausen was cleared after sideline testing, but had delayed symptoms following a big hit in last weekend's game versus the Bengals.
In the fourth quarter last weekend versus the Bengals, Bears quarterback Jimmy Clausen took a shot to the head as he attempted to slide, and was immediately taken to the sideline for testing for concussion symptoms.
Initially, the Bears cleared him for a concussion, but kept him on the sideline the remainder of the game. Later that night, apparently, Clausen began showing delayed signs, and it was later confirmed that he did in fact have a concussion.