Eric Berry left the field with a knee injury, and he never returned.
From KC Star’s Red Zone blog:
But there was concern inside the locker room that the injury could be serious. Berry was tended to earlier in the contest before returning; a few minutes later, the second-year safety was helped off the field.
If this an ACL injury Berry could be done for the season. It would be a terrible blow to the KC defense that struggled mightily without one of its best players.