At 7:19 of the second period, Fraser was hit into the boards by Maple Leafs forward Frazer McLaren. Fraser needed help off the ice after McLaren finished a check on him in front of the Maple Leafs' bench.
Fraser did not return to the game. He has one assist in 17 games this season.
"He obviously got his bell rung," Kings coach Darryl Sutter said. "We don't really know much yet."