Safety Matt Bowen is listed as day-to-day after re-injuring his right knee during Wednesday's practice, team officials said.
The injury is not considered serious. Bowen is unlikely to play in Friday's preseason game against the Cincinnati Bengals at FedExField, however.
Bowen sustained a mild sprained MCL injury during practice and was carted off the field. It's the same knee that Bowen had season-ending surgery on last October to repair a torn ACL.
"We had a scare there with Matt tweaking his knee," head coach Joe Gibbs said. "The doctors took him in [from practice] just to make sure that we can do everything we can here to look at it."
The Redskins' secondary has been hit hard with a series of nagging injuries this preseason. Safety Ryan Clark also has a sprained knee and is expected to sit out Friday's preseason game. Like Bowen, Clark's injury is not believed to be serious.
Cornerbacks Shawn Springs and Carlos Rogers returned to practice this week after they both missed last Saturday's game against Carolina. Springs had a sore hamstring and Rogers had an ankle injury.
Walt Harris sustained a calf injury in last Saturday's preseason game at Carolina that forced him to miss practices earlier this week.
Cornerback Artrell Hawkins and safety Tony Dixon have both been sidelined with hamstring injuries. Cornerback Garnell Wilds has missed time due to a thigh bruise.
Meantime, running back Clinton Portis has been nursing a sore elbow and he may not play in Friday's game against Cincinnati.
"It is not too big of a deal, but it keeps agitating and worrying us," Gibbs said. "Since he's a running back, he ends up going on there and landing on his elbow, and it gets aggravated.
"It is something that we will evaluate on Thursday and make our decision on it later."