Both players were hurt in the Nov. 16 game against Philadelphia, Whitworth with an ankle injury and Kooistra with a knee injury. They were inactive for last week's game at Pittsburgh.
The club also signed rookie offensive tackle Kirk Barton from the Miami practice squad and first-year cornerback Geoffrey Pope from Cincinnati's practice squad.
Barton played one game for Chicago and Pope played in three Cincinnati games this season.
Copyright 2008 by The Associated Press