Capitals' backup goalie Brent Johnson sprained his left knee late in the first period of a 4-3 overtime loss in Pittsburgh on Thursday night and will be out at least a week. The Capitals also played most of the third period without star Alex Ovechkin, who needed a several stitches to close a cut on his leg. Ovechkin, whose 26th goal had given Washington a 3-2 lead, played only about 1 1/2 minutes in the final period even though his injury was minor.