Hossa laid face-first on the ice for a few minutes while being attended to by the Blackhawks medical staff. He eventually got to his knees and then went to the locker room under his own power. He did not return to the game. Hansen was given a two-minute penalty for roughing.
Hawks general manager Stan Bowman told ESPN.com NHL Insider Craig Custance that Hossa wasn't hospitalized from the hit and that the initial signs were better than they were after Hossa was hit by the Phoenix Coyotes' Raffi Torres in last year's playoffs. That hit resulted in a concussion that ended Hossa's season.
"We hope he's back soon," Bowman said. "We'll know more once he comes in and sees how he feels the day after."
Blackhawks coach Joel Quenneville didn't have a definitive update on Hossa, but said he spoke with him after the game.
"He seemed OK, but we'll know [Wednesday]," Quenneville said.
Hansen has a hearing regarding the hit Wednesday at 3:30 pm ET with the NHL, the league said on its website.
Blackhawks captain Jonathan Toews doesn't believe Hansen was going for the puck when he made contact with Hossa.
"I saw it when the puck was up," Toews said. "I saw the replay on the board. It was pretty evident he wasn't reaching for the puck or anything. I'm not too sure what's going to happen there. I'll have to see it a few more times to comment further, but I don't think there's any doubt there's contact to the head there. We just hope Hos is going to be OK."
Quenneville passed on offering his opinion of the hit.
"I think everybody saw it," Quenneville said. "Everybody can have their own opinion. We'll let the people who do that stuff do their job."
Hansen called the hit "a hockey play" and said he and Hossa "ran into each other."
"I think I kind of grazed on the back of his shoulders, and then he goes down," Hansen said. "I don't see what happens afterward because the play continues a little bit. First when I'm looking back, I see that he's down. Not quite sure what's going on."
Canucks coach Alain Vigneault said Hansen didn't do anything illegal on the play.
"It wasn't even a penalty," Vigneault said. "Both referees looked at the play. Until Toews went out to talk to them, it wasn't even a penalty."
Vigneault doesn't believe Hansen will be punished for the hit.
"Not a chance, not a chance," Vigneault said. "He was trying to grab a puck in the air. It's unfortunate if the young man is hurt. [Hansen] was trying to jump to get the puck. Stuff happens."
Hossa suffered a head injury last season when Torres launched himself into Hossa during Game 3 of their first-round playoff series on April 17. Hossa had to be taken off the ice on a stretcher and missed the Blackhawks' final three games of the season. He was cleared to play again in early December.
"I think we're all concerned at this point, especially after what happened last year," Blackhawks forward Patrick Sharp said. "But Hos is a tough guy. We just got off the ice, so I don't have any update or haven't seen him. But obviously if it's Hos or any of my teammates, I'm concerned."
Hossa scored two goals in the second period of Chicago's 4-3 shootout win Tuesday night before being injured. He had scored just once in the previous 11 games and has eight goals on the season.
Sharp said Tuesday's game was similar to many the Blackhawks and Canucks have had in recent years.
"There's some big hits out there, some questionable hits, both sides," Sharp said. "I think that's to be expected when these two teams face each other. There's obviously a lot of bad blood. We've seen each a ton over the past four seasons. That's going to happen. It's just tough when you seen injuries."
A lower-body injury suffered during Sunday's win over the Los Angeles Kings kept Seabrook out against the Canucks. Crawford missed his third straight game with an upper-body injury.
Information from ESPN.com's Pierre LeBrun was used in this report.