CSN Bay Area

UPDATE (3:10 p.m. on Wednesday) -- The Raiders officially signed unrestricted free agent defensive tackle Dan Williams, the team announced in a press release.

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The Raiders bolstered their interior defensive line on Wednesday morning with the addition former Cardinals defensive tackle Dan Williams, CSN California has confirmed.

Contract terms were not immediately known. 

Williams, the 26th overall pick in the 2010 draft, played nose tackle in Arizona's 3-4 defensive scheme. He started nine games for Arizona last season, registering one sack and 32 tackles. 

He'll play the interior in the Raiders' 4-3 base defense and should improve the team's run defense. Second-year pro Justin Ellis will aid Williams in that effort. 

The Raiders were linked to former Broncos defensive tackle Terrance Knighton, but he crossed Oakland off his list. 

"The Raiders made me an offer but it's not close to what I was looking for,” Knighton told ESPN's Josina Anderson. “So, as of right now, the Raiders and Broncos are out of the race. A lot of people had me going to the Raiders because of Jack Del Rio, but I'm now focusing on a few other teams right now."