NAPA -- The Raiders welcomed 15 players to training camp Thursday who signed contracts since the lockout ended and said a temporary goodbye to running back Darren McFadden.
Their most explosive offensive player, McFadden was not present and is out at least two weeks with a fractured orbital bone, or eye socket, an injury suffered during practice Wednesday.
Coach Hue Jackson described it as "a small, little fracture of his orbit. So he'll be out a couple of weeks."
After practice Wednesday, McFadden's face was unmarked, and he didn't seem to be in any pain as he stopped and talked with reporters.
With wide receiver Jacoby Ford out with a broken bone in his left wrist, the Raiders will go through the majority of the 31/2-week training camp without two players who combined for 17 touchdowns last season.
Jackson said he wasn't sure when the injury occurred, but McFadden sat out the rest of practice Wednesday after locking up linebacker Quentin Groves and driving him backward during a pass-blocking drill.
McFadden also missed two weeks of training camp with a hamstring pull last season.
The absence of McFadden came on a day when the collective bargaining agreement was ratified, enabling signed free agents to practice. The Raiders were still undermanned, though, as 15 players missed practice because of injuries, and a 16th, wide receiver Derrick Jones, had to be helped from the field during the padded session.
Oakland was particularly thin at running back, because fourth-round draft pick Taiwan Jones and Michael Bennett were out with undisclosed injuries. With restricted free agent Michael Bush not reporting to camp, that left all the work to Rock Cartwright and Louis Rankin.
Bush can sign with another team, but the Raiders have the option either to match the contract or receive a first-round draft pick in return. He'll make $2.6 million upon signing a one-year deal.
Asked if he's talked to Bush and knows when the running back will arrive, Jackson said, "Yes, I do, but I can't tell you that, but I'm very comfortable that at some point in time Michael will be back here with us."
The Raiders front office, meanwhile, was crunching numbers to get the club under the $120.4 million salary cap. Teams were supposed to be cap compliant Thursday, but they received memos Wednesday giving them 24 more hours. Oakland was reportedly $15 million to $17 million over in recent days.
ESPN reported defensive lineman Richard Seymour had restructured his contract with a cap savings of $11 million, as well as cornerback Stanford Routt. Seymour declined to discuss his contract, and Routt said he was willing to help clear space.
"I'm here to help the team," Routt said.