Walker, a second-round pick of the Raiders in 2002 who started 33 games in five seasons in Oakland, was most recently with Buffalo before getting cut by the Bills six days before the season-opener.
"Hopefully I can come in and help this team at some point, once I take the field," Walker said. "If not, I'll definitely give these guys a look on the practice field."
Walker was signed to shore up an offensive line that gave up six sacks in last week's loss to the New York Giants. Right tackle Cornell Green was injured and did not play, while left guard Robert Gallery has been out for several weeks with a broken leg.
Erik Pears started at right tackle against the Giants but both he and left tackle Mario Henderson struggled in pass protection. As a result, quarterback JaMarcus Russell – already under fire – spent much of his afternoon on the run.
Because of his addition at mid-week, Walker likely won't start but could be in the lineup for the Jets game on Oct. 25.
"I'm not gonna lie to you and tell you that I saw it coming," Cable said. "But you know, they made their decision, and Oakland has me back."
Walker's weight was up to 380 at one point this year but he's dropped to 362, still not ideal for the Raiders' zone-blocking schemes but something Cable feels Oakland can work with.
"We'll see if he can get in and learn the system, and see if he can do our system," Cable said. "You can't just say he'll be ready at such and such time. He's got a lot of work to do to get there. He's quick off the snap. Let's see how he does it as he gets into it and gets familiar with it."
By placing O'Neal on the waived injured list, the Raiders still have a chance to retain his rights. If he is not claimed within 24 hours, he goes back on Oakland's injured reserve list.
O'Neal has been trying to come back from major knee surgery last year and was dealing with a severe ankle sprain when he was let go.
Raiders sign Walker,waive O'Neal
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