Raiders place LB Ricky Brown on IR

ALAMEDA, Calif. -- The Oakland Raiders have placed linebacker Ricky Brown on injured reserve with a concussion and activated fullback Manase Tonga from the practice squad.

The Raiders are thin at fullback heading into Sunday's game at Houston. Starter Marcel Reece is questionable with an ankle injury and his replacement, Richard Gordon, is out after breaking his hand last week.

Brown got a concussion against the New York Jets on Sept. 25. He missed last week's game against New England.