Britton tore the labrum in his right shoulder during Sunday's 42-20 loss at Kansas City, will have surgery and be sidelined at least four months.
Pears, a 6-foot-8, 305-pounder from Colorado State, has started 30 games since entering the NFL as an undrafted rookie with the Denver Broncos in 2005. After four seasons with the Broncos, he signed with Oakland in 2009. He spent the 2010 preseason with the Raiders before he was waived in final cuts.
Jordan Black will start in Britton's place, and Pears will provide depth at the position.
Copyright 2010 by The Associated Press