NAPA, Calif. - The Oakland Raiders signed Adam Archuleta to a contract on Monday in a move to add depth to their defense.

In this July 29, 2007 file photo, Chicago Bears safety Adam Archuleta jogs to the field for team football practice in Bourbonnais, Ill. The Oakland Raiders agreed to terms on a contract with Archuleta on Monday, Aug. 11, 2008 in a move to add depth to their defense. (AP Photo/M. Spencer Green)

Archuleta was at the Raiders facility Monday morning and left with trainer Rod Martin to take a physical. Archuleta was expected to take part in the night practice. Oakland released safety Greg Wesley to make room on the roster.

Archuleta has been a safety in the NFL but played linebacker in college at Arizona State. He could contend for a spot as a backup safety or for the starting strong side linebacker job in Oakland.

Ricky Brown, Robert Thomas and Sam Williams are competing for the starting role at linebacker alongside Kirk Morrison and Thomas Howard.

Coach Lane Kiffin said after the morning practice that he wanted to bring more players into camp to create more competition for jobs and improve the team's depth.

"It's been a situation that unfortunately, we haven't brought guys in," he said. "I control what I can control, come out every day and get our guys as good as we can. I'm pleased with the top of our roster but we need to add to the bottom of our roster. We need more competition."

Archuleta was cut in May by Chicago after one disappointing season with the Bears. He broke a hand early last season and started in just 10 of the 15 games in which he appeared. He lost his starting job to Brandon McGowan and finished the season on special teams.

"He's a great guy with talent, a good nose for the ball, he brings a lot to the game. I'm excited to have him here," said Thomas, who played with Archuleta in St. Louis. "He can cover tight ends, play defense, play the run, so I'm excited to have him."

Archuleta, a first-round pick by St. Louis in 2001, has been known throughout his career as a hard-hitting tackler who has struggled at times in coverage in the secondary.

His career has gone downhill since signing as a free agent with Washington in 2006. He received the largest contract given to a safety, $30 million for six years, with a $10 million bonus. But he ended up starting only seven games and played mostly on special teams before being traded the following year to Chicago for a sixth-round draft pick.

Archuleta has started 86 of his 103 games in the NFL, making 423 solo tackles and intercepting four passes.

Wesley was signed the week before training camp to provide a boost to the secondary but was limited by a back injury before being released.