The Raiders had the NFL's third-ranked overall defense and No. 1 ranked pass defense last year, despite finishing with an NFL-worst 2-14 record.

Darius could challenge incumbent starter Stuart Schweigert for playing time, adding veteran leadership to a young secondary. Michael Huff, the team's first-round pick in 2006, is at one safety position, while 2005 first-rounder Fabian Washington and 2003 first-rounder Nnamdi Asomugha are entrenched at cornerback.

"This is an organization that I feel is heading in the right direction with the new coaching staff and the players," Darius said. "I am very optimistic about the change that is taking place within the team."

Darius, who turns 32 next month, had been a mainstay in Jacksonville's secondary since he was the club's first-round pick in the 1998 draft. But the Jaguars released him in June as they try to get younger and faster on defense.

Raiders coach Lane Kiffin worked with Darius previously when he was Jacksonville's defensive quality control coach in 2000.

"He will bring us strong competition and he gives us added flexibility in our secondary," Kiffin said. "Donovin exemplifies hard work and dedication to the game. Working with Donovin at Jacksonville, I was able to see what a phenomenal competitor he is. He will fit great into our team philosophy."

Darius finished his career in Jacksonville with 614 tackles, 14 interceptions, eight forced fumbles, six fumble recoveries and two sacks.