Lupul was hurt in the second period and will return to Toronto for further evaluation, the team said in a news release. The veteran left-winger has 17 points (nine goals, eight assists) in 26 games this season.
Forward Peter Holland suffered an upper-body injury in the game and will also undergo further evaluation in Toronto. He has 16 points (8-8) in 38 games this season.
The Maple Leafs also recalled forward Greg McKegg from the Toronto Marlies of the American Hockey League. He has 15 points (7-8) in 23 AHL games this season.
Toronto continues its seven-game road trip Friday night at Minnesota.