The young left tackle was called for three penalties, all in about a 10-minute span late in the second quarter of Oakland's preseason loss to Dallas on Friday. Two of the calls against Walker came on illegal formation calls, the third on a false start.
The illegal formation penalties were particularly concerning to the Raiders because early in training camp the team was briefed on rule changes regarding alignment of the offensive linemen. NFL officials are trying to crack down on linemen easing back in their stance too far and have put teams on notice that that will be an area that will be heavily scrutinized this season.
''The tackles, their (helmet) has to break the plane of the center's waist,'' explained Oakland head coach Bill Callahan. ''If that hat's tipping back a little too far, they're going to call it.''
One of the illegal formation calls against Walker negated a long pass interference call against Dallas that would have put the Raiders in prime scoring position deep in Cowboys territory.
Nevertheless, Callahan said he was pleased for the most part by what he saw from Walker.
''Aside from the penalties he played pretty well,'' Callahan said. ''He didn't get beat, he stood the test, he was strong at it and he was physical. He's trying to gain confidence and he has a lot of things going on in there. We'll straighten that out.''
NOTES: X-rays on safety Ray Perryman's right ankle were negative and he will be listed as day-to-day. Perryman was injured in the third quarter against Dallas while trying to make a tackle when he was hit by teammate Napoleon Harris and got his leg tangled up in the ensuing pile ... Callahan said that cornerback Charles Woodson, who was held out of the game against the Cowboys, will play in Thursday night's game against Tennessee.