Edwards' back acts up; Vikes say it's not serious

MANKATO, Minn.—Vikings defensive end Ray Edwards has aggravated a lingering back injury and will start training camp on the physically unable to perform list.

Coach Brad Childress revealed the problem Thursday afternoon, but said the move was precautionary and referred to the condition as "a little twinge."

Edwards is slated to start at left end this season after switching spots to accommodate Jared Allen. He has been bothered by the injury since minicamp in early June, but he had been on track to be ready for the beginning of camp.

Childress said he believes the setback was caused by overworking.