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SAN FRANCISCO (KCBS) – The San Francisco 49ers added a big piece to their defense on Thursday, signing Darnell Dockett to a two-year contract.

Dockett had spent all 10 seasons in the National Football League with the team’s NFC West rivals, the Arizona Cardinals.  John Madden said the move should help the defense, as long as Dockett is healthy.

“You assume that coming off the surgery, that he’s as healthy as can be.  He’s a guy that plays inside and raises havoc,” Madden said.  “You want him on your side.  If he’s on your side, he’s a real tough guy .  If you play against him, he may border on playing dirty.  But that’s kind of the guy you want.”

Dockett sat out the entire 2014 season after suffering a knee injury in training camp with the Cardinals.  Madden said that if defensive lineman Justin Smith comes back to the 49ers, he and Dockett would make a formidable pair.