Orpik was taken off the ice on a stretcher after Thornton grabbed him from behind and knocked him down before throwing a punch. Orpik appeared to hit his head on the ice when he fell. Thornton was given a match penalty.
Thornton challenged an unwilling Orpik after the Pittsburgh defenceman gave what Cherry described as "a good licking" to Loui Eriksson.
Cherry noted that the incident wasn't a fight, adding "let's get that straight."
Orpik was surrounded by members of both team's medical staff before he was taken off on a stretcher after about a 10-minute delay.
He was taken to Massachusetts General Hospital, and he was alert and conscious, the Penguins said in a release.
Cherry also used his Coach's Corner segment to air his grievances over the selections for Canada's junior team. While Cherry said everyone who is on the team deserves to be there, he also said he couldn't believe Erie Otters winger Connor Brown, who leads the Ontario Hockey League scoring, didn't get an invite.
Brown was a first round pick of the Toronto Maple Leafs.
Cherry also wondered why Maxi Domi of the London Knights, who had 32 points in 21 OHL playoff games last season, didn't get an invite, adding "and you're wondering why we lose."