Rookie Denarius Moore was held out of Wednesday's practice and wore a protective boot on his right foot, while veteran T.J. Houshmandzadeh also sat out the workout.
With Jacoby Ford still mending from a foot injury and Darrius Heyward-Bey recovering from a concussion along with spine and neck injuries suffered last week in Minnesota, the Raiders are down to a handful of healthy receivers, including Chaz Schilens, Louis Murphy and rookie Eddie McGee, who is on the team's practice squad.
"It's a concern but I think we have a chance to get some of these guys back toward the end of the week," coach Hue Jackson said. "Am I concerned about it? Yeah. Anytime you don't practice it's tough. But I think we'll be OK."
Moore has been Oakland's best deep threat in his first NFL season and has developed into one of quarterback Carson Palmer's favorite targets.
Moore, who has 23 catches and a team-leading four touchdown receptions, injured his foot in the second half of last week's win in Minnesota and has been wearing a walking boot ever since.
"It makes it difficult," Palmer said of the injury-plagued receivers. "You don't get the same guys on the field from the week before, that rhythm and timing thing slows down a little bit. So we have our work cut out for us."
According to the league injury report, Houshmandzadeh's absence from practice was non-injury related. He has caught just two passes for 35 yards since signing with Oakland as a free agent on Nov. 1.
Notes: Quarterback Jason Campbell, out since suffering a fractured clavicle against Cleveland on Oct. 16, has not resumed throwing but is getting closer. "I think he tried a little bit and it just wasn't there," Jackson said. "It's going to take some time." ... Cornerback Chris Johnson practiced for the first time since being sidelined with a groin injury in late September.
Copyright 2011 by The Associated Press