The 26-year-old defenseman was taken to a hospital, where he had testing before being released.
"He was going through a crosswalk," general manager Brad Treliving said in comments tweeted by the Flames. "The good news -- and the most important thing -- is that 'Ras' is doing well. He was transported by ambulance to Detroit Receiving Hospital.
"I don't want any speculation out there. There was no alcohol involved."
Andersson will remain with the Flames, who lost 2-1 at the Detroit Red Wings on Thursday in the third of a five-game road trip. He has 34 points (seven goals, 27 assists) in 51 games this season.
"He won't play tonight, and we'll take this real slow ... not anything that we're overly concerned about," Treliving said. "But he got hit, so we're going to see how things go over the next 24 hours and go from there.
"He's doing well, in good spirits. We're lucky, very lucky. It certainly could have been a lot worse. We want to make sure that we thank all those involved (in his care) and let everybody know that Ras is doing well."
Andersson has played seven seasons for the Flames since they selected him in the second round (No. 53) of the 2015 NHL Draft.
"You're shocked. It could have been a lot worse," Calgary forward Mikael Backlund said. "We're just happy he was OK. When he got back to the hotel, he was doing better. But yeah, very scary, scary moment, for sure."
Defenseman
Dennis Gilbert
was recalled from Calgary of the American Hockey League on Thursday. He had one shot on goal, one hit and one blocked shot in 12:52 of ice time.
