The San Francisco 49ers today announced they have claimed LB Ray-Ray Armstrong off waivers from the Oakland Raiders. In order to make room on the roster, the team placed DT Glenn Dorsey on the Injured Reserve List.

Armstrong(6-3, 220) has appeared in 41 games (five starts) and registered 47 tackles, 1.0 sack, one forced fumble and one fumble recovery during his three years in Oakland and St. Louis. He originally signed with the St. Louis Rams as an undrafted free agent on May 9, 2013 where he appeared in 20 games for the Rams before being waived by the team on October 6, 2014. He was claimed by the Oakland Raiders the following day and appeared in 11 of the team's final 12 games. This season with Oakland, Armstrong played in each of the team's 10 games (two starts) where he registered 17 tackles, as well as five tackles on special teams, before being waived on November 24, 2015.

A 24–year-old native of Sanford, FL, Armstrong played collegiately at the University of Miami where he appeared in 30 games and registered 134 tackles, four interceptions, two forced fumbles and six passes defensed. He earned Second-Team All-ACC honors as a sophomore in 2010.

Dorsey (6-1, 297) started in each of the team's first 10 games this season and registered 36 tackles and 1.0 sack.