The 29-year-old Lupul was in front of the net during a power play midway through the second period when a slapshot from teammate Dion Phaneuf smashed into his arm. Lupul left the game immediately and did not return.
Lupul signed a five-year contract extension with the Maple Leafs on Sunday. He led Toronto with 25 goals and 42 assists last season and made his first All-Star team. Lupul had yet to score for the Maple Leafs this season at the time of the injury.
I don't think today was my most solid game that I've had, some rebounds here and there. I know there's a lot of work to do, not every game is going to go as good as these last few. I've just got to make sure I keep working and keep trying to get better.
— Los Angeles Kings goaltender Martin Jones after stopping 38 of 39 shots in a 3-1 win over the Toronto Maple Leafs