Dahlen suffered an apparent arm injury and won't return to Saturday's game versus the Capitals, Sheng Peng of San Jose Hockey Now reports.
Dahlen suffered the injury late in the first period and got back into the game during the second, but he later retreated to the locker room again for good. The Sharks have little reason to risk the long-term health of the 23-year-old. If he's forced to miss time, it'll be a big absence, as he has nine points in 16 appearances while playing in a top-line role this year.