The team's first overall pick in the April NFL draft likely will miss 10-14 days, The Washington Post said.
The former Michigan State product was carted off the team's practice facility in Ashburn, Va., after running down the right sideline for a deep pass from quarterback Jason Campbell.
It was Washington's third major injury in its first week of training camp.
"There was nothing I could say," exasperated Coach Jim Zorn said of the team's training camp injuries. "Here we go again."
The Redskins Sunday lost defensive ends Phillip Daniels and Alex Buzbee to season-ending injuries. Daniels tore a left-knee ligament and Buzbee ruptured his Achilles tendon.
The team said Sunday it had acquired veteran defensive end Jason Taylor from the Miami Dolphins in exchange for two draft picks.
Defensive end Chris Wilson was sidelined Thursday by a left calf strain.