The Seahawks added an experienced veteran to their secondary Wednesday, signing former San Francisco 49ers starting cornerback Tramaine Brock. Seattle also added depth at linebacker, signing Rodney Butler. Receiver Jamel Johnson was waived and safety Jordan Simone was waived/injured.

Brock, 28, went undrafted in 2010 out of Belhaven College, and spent his entire career in San Francisco before being released this offseason. Following an injury-shortened 2014 season, Brock started 31 of 32 games over the past two years, recording four interceptions and 25 passes defensed. Over his seven year career, Brock has 181 total tackles, 11 interceptions and 43 passes defensed.

Butler, an undrafted rookie out of New Mexico State, led the nation in tackles as a senior with 165. He took part in Seattle's rookie minicamp as a tryout player in May.

Johnson signed a future contract with Seattle after the 2016 season. He was waived in May, then re-signed earlier this month. Simone, a Skyline High School product, signed with Seattle this offseason after taking part in rookie minicamp as a tryout player. He sustained what Seahawks coach Pete Carroll said was an ACL injury during Seattle's preseason opener at Los Angeles. If Simone clears waivers, he will be placed on injured reserve.