NAPA The Raiders have yet to put their projected first-team defense on the field, but that day might be growing near.
Tackle Pat Sims, who had been sidelined since Aug. 7 because of a hamstring injury, went through drills and participated in a couple of team sessions Tuesday. He joined tackle Vance Walker, who returned Monday following a lengthy absence because of an undisclosed injury.
Coach Dennis Allen isn't sure when Sims will rejoin the first team or if he'll play in the preseason. But slowly but surely, the Raiders' defense is getting healthy.
Cornerback Tracy Porter is out with a groin injury, giving first-round pick D.J. Hayden a chance to start Friday's preseason game against Chicago.
Strong safety Tyvon Branch sat out the last two practices with sore ribs, but Allen doesn't consider the injury serious.
Considering the Raiders plan on opening the season with nine new defensive starters Branch and end Lamarr Houston are the only holdovers they ideally would have had a few practices together.
The defensive philosophy of Allen and general manager Reggie McKenzie emphasizes a mixture of man-to-man and zone coverages, several blitz variations and dropbacks into coverage.
It's a much more complex mix than the old standard Raiders defense, which called for a four-man rush and press coverage. Players have been acquired partly for their attention to detail and business-like approach, but being attentive in meetings will take the defense only so far.
"Make no mistake about it, when you miss time you do fall behind a little bit, and it takes a little time to catch up," Allen said.
The deadline for the Raiders to put their defense together is Sept. 8, when they open the regular season in Indianapolis. Can they be ready by then?
"We really don't have a choice," Walker said. "Honestly, I think we'll be just fine."
Middle linebacker Nick Roach, the defensive signal caller, said the defense's on-field time together will accelerate the process of becoming a unit.
"It's coming along," Roach said. "The more we get to play with each other, the more improvement you'll see. The last two games we've gotten our fits better, anticipating where we're going to be."
Defensive coordinator Jason Tarver said there is more communication between the defensive backs and the linebackers than with the defensive line, so he put in some extra drills so Roach and outside linebacker Kevin Burnett can get used to playing directly behind Walker and Sims.
Tarver considers Sims, whose role as a run stopper is crucial, to be good in carrying out assignments and knowing the playbook.
"I'm up to speed with everything," Sims said. "It's just about getting through the motions and getting used to the guys you're working with. Of course it's going to take some time. I believe we can be a very good unit. It's a matter of us all being healthy at the same time and being able to practice together."