Coach Dave Cameron announced Friday that Lehner's upper-body injury has been diagnosed as a concussion, Wayne Scanlan of the Ottawa Citizen reports.Cameron confirmed the concussions for both Lehner and forward Clarke MacArthur, who collided with each other during Monday's loss to the Hurricanes. Lehner will remain under the league's concussion protocol until his symptoms begin to subside, but the volatile recovery timetable for the head injury makes it difficult to speculate when he might be cleared to return. Like Lehner, Craig Anderson (hand) also remains listed on injured reserve, leaving Andrew Hammond as the team's primary netminder for the foreseeable future.