Redskins Coach Mike Shanahan said that fullback Mike Sellers injured his back during a rowing exercise in the weight room and went to the hospital.
The coach expects Sellers to spend the night in the hospital.
Cornerback DeAngelo Hall (hip) and tackle Trent Williams (ankle) did not practice.
Linebacker London Fletcher (hamstring) was limited in practice. Also limited was Rex Grossman (pneumonia).
Shanahan said the team might have put Chris Cooley on the PUP list to start training camp had the lockout not prevented the team from evaluating him during the offseason. Had the team been able to find out how weak his knee was ahead of time they might have gone the PUP list route to give him more time to recover.
Safety Kareem Moore continues to progress as he continues to practice while being evaluated by coaches before they decide whether or not to activate him from the PUP list.