The earliest Olsen could return is in three weeks, but that of course depends on the severity of the injury. Head coach Pete Carroll has described the injury as a "fascia tear."
With 23 catches and 224 receiving yards this season, Olsen leads aLl Seattle tight ends.
Also on Monday, the Seahawks signed DT Damon "Snacks" Harrison.
He's been on the practice squad since week 10 against the LA Rams, and he played last week against Arizona.