Coach Pete Carroll said he wasn't sure how serious it was.
Ryan was injured on Devin Hester's 89-yard punt return for a touchdown, when Chicago's Earl Bennett lowered his shoulder and leveled him with a block. Hester's touchdown equaled an NFL record with his 13th kick return for a touchdown.
Ryan stayed down for several minutes before walking off the field.
The Seahawks also lost cornerback Kelly Jennings to a hamstring injury in the first quarter.
Copyright 2010 by The Associated Press