Notes from yesterdays practice: Nothing real big to note but Hall getting beat again on a pass.

– Whatever is ailing Nnamdi Asomugha is also ailing Jarrod Cooper, as both missed practice. Asomugha, according to Lane Kiffin, has been treated with IVs and is expected back Wednesday morning.

– JaMarcus Russell continued to spend much of his time in seven-on-sevens and team sessions playing it safe, throwing to backs swinging out of the backfield or over the middle.

He may be making Rich Gannon seem like a mad bomber, but it is what Kiffin and the offensive staff want as part of Russell’s development. Still, it is at least a little disturbing that few wide receivers seem to be breaking into the clear.

There doesn’t appear to be a clear No. 1 receiver on the roster after 13 days of camp, meaning the Raiders _ and big-bucks free agent signee Javon Walker in particular _ have time to get better with the first preseason game coming up Friday night against San Francisco.

When asked about the dearth of open receivers, Kiffin noted that the Raiders have a good coverage secondary as well as Walker’s one-practice-a-day schedule. It didn’t help that Drew Carter, who looked terrific in early practices but seems to have slowed lately, was given practice off to get his legs back under him.

“I think the quarterback is doing exactly what we want and we’d like to get open more often for him,” Kiffin said.

The Raiders secondary was without Asomugha, Cooper and starting strong safety Gibril Wilson, who is resting a sore knee which Kiffin said is not serious. Wilson probably won’t see much time against San Francisco, Kiffin said.

– When Russell plays, Kiffin said he would be careful to make sure he has the best possible supporting cast in terms of pass protection. The best pass blockers are likely to play as long as Russell does.

– Wide receivers coach James Lofton continued to school his young receivers, hoping to get more consistency. A drop by Drisan James, who turned late and let a Marques Tuiasosopo pass glance off his hands, caused Lofton to bellow, “Make the play, make the play, make the play!”

When cornerback Darrick Brown made a more aggressive play on a corner route than wide receiver Chaz Schilens, with Brown knocking it away, Lofton yelled, “Be aggressive! You have to go up and get it. You wait for it, you get nothing.”

Arman Shields was lectured for catching a pass and leaving the ball where it could be knocked loose by a defender.

“You’ve got no chance with that ball in the inside arm. No chance,” Lofton said.

Shields also dropped one of Russell’s few deep throws after getting behind Stanford Routt.

– Defensive end Greg Spires has come on of late and made a nice play when he blew up a pitch to Louis Rankin the backfield.

– Some of the day’s best intermediate throws were not made by Russell, but by Tuiasosopo, particularly a sharp, perfectly-timed 20-yard out to Todd Watkins in front of DeAngelo Hall.

– Watkins later dropped a pass _ on a Tuiasosopo throw which as slightly behind him. It was one of his few drops since camp opened.

– Quarterback Andrew Walter rested a sore arm again but Kiffin said he expected him to play against San Francisco.

– Kiffin said running back Darren McFadden will get enough preseason time to determine how well he takes a hit and to prove his ball-security issues while at Arkansas are behind him. He will not return kickoffs against the 49ers.

– The mission for Michael Bush Friday night couldn’t be more clear. Kiffin wants a hammer.

“Run physical, run hard,” Kiffin said. “He’s 246 pounds _ don’t run like a 200-pounder . . . he’s the one big guy we have, and if he can what we hope he can do I think we’re in a real good position there.”

– Robert Thomas has been running with the first team at strong side linebacker for three days, but apparently that has more to do with a previously undisclosed injury to Ricky Brown than it does with Brown moving on to the first team.

“Ricky being banged up and not out there is a big reason for that,” Kiffin said. “Robert is playing `Mike’ and `Sam’ for us. Robert’s got to play special teams and I’ve talked to him about that, and he’s going to have to do it all to make the team.”

Kiffin said of the linebacker position: “There are only two guys that I know are going to make this team and the rest of the guys had better play special teams and contribute.”

Brown, Kiffin said, has knee and back issues but should play against the 49ers.

– NFL officials are on hand at practice and will go over rules changes with players, coaches and the media. It was amusing to watch an official throw a flag on Hall for pass interference against Arman Shields, only to get an earful from Hall of Fame corner and secondary coach Willie Brown.

“He doesn’t have the right of way. Don’t let him tell you that `right of way’ stuff,” Brown said to Sheilds before a brief debate with the official about what constitutes legal and illegal contact.

– Jack Tatum attended his first practice of the season and was signing autographs for fans who were invited guests, as the Raiders hosted radio advertisers. Tatum said he hadn’t yet seen Wilson play at safety with the Giants but was encouraged to hear about his hitting and tackling with the Giants.

“Good, that’s what we need,” Tatum said.

– All eyes were in the south end zone when Russell was stretched out on the ground, with trainer Rod Martin working on his knee. No worries. Russell got back up and rejoined drills.