The National Hockey League on Thursday suspended the Maple Leafs forward two games for an illegal check against Tampa Bay defenceman Victor Hedman in Toronto's 4-2 win the previous night.
Lupul, playing his second game since returning from a 25-game absence with a broken forearm, had a goal and assist before he levelled Hedman early in the third period, leaving the 22-year-old Swede shaken up.
Hedman, who has had previous concussion issues, had dumped the puck in the Leafs' zone when Lupul left his feet and struck him to the side of the head with a high hit near the Toronto blue-line.
"I've got to see the replay, but by no means did I go after him and try and hit him in the head," Lupul said after the game Wednesday.
The league ruled that Lupul "recklessly targeted" Hedman's head.
Hedman left the game but later returned.
Lupul was assessed a minor penalty on the play for an illegal check to the head.
The 29-year-old has scored three goals and four points in five games this season.