The Seahawks also placed linebacker Nick Moody on injured reserve and signed wide receiver B.J. Daniels from the practice squad. Moody was hurt in Sunday's win over San Francisco.
Brown is in his second stint with the Seahawks, but could be active for the first time this season with Marshawn Lynch not expected to play on Sunday against Pittsburgh. Seattle played last week against San Francisco with just two running backs active, Thomas Rawls and Fred Jackson.
The signing of Daniels may be protective in case Doug Baldwin is slowed this week by an ankle injury suffered against the 49ers.
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