Salo and Ohlund, two of Vancouver's top three defenders, were hurt at the Torino Olympics last week.
Sweden's Ohlund injured his ribs and left shoulder sliding into the end boards during a quarterfinal win over Switzerland.
Salo hurt his right shoulder and chest in a collision with a Finnish teammate late in their quarterfinal victory over the United States.
The Canucks already are without Ed Jovanovski, who is expected to miss most of the rest of the regular season after abdominal surgery. That means they will be missing their top three defensemen when their three-game trip starts in Calgary on Tuesday night.
Ohlund returned to Vancouver on Friday for evaluation. X-rays showed no fractures in his ribs. He said he hopes to join the team either in Nashville on Thursday or Chicago Friday.
"It's never good when you're injured and missing days, but it's definitely not something that is going to keep me out for long," Ohlund said. "I haven't skated yet so that's going to be a big test, but I do feel pretty good."
Salo stayed in Italy to watch the rest of Finland's games and was scheduled to return to Vancouver on Monday night. Until then, the Canucks won't know the full extent of his injuries, which has frustrated general manager Dave Nonis.
Gold-medal winning twins Daniel and Henrik Sedin, who attended a Swedish celebration in Stockholm on Monday, are expected to be in Calgary in time for the game. Henrik is second on the team in scoring with 57 points, while Daniel is fourth with 51 points.
Defenseman Nolan Baumgartner (foot) skated also is a game-day decision for the Flames.
Mojzis, a 23-year-old rookie, has played five games for the Canucks this season, recording one assist.
Butenschon, 29, is an AHL All-Star who has 132 games of NHL experience and played three games for the Canucks this season.
Vancouver goes into Calgary trailing the Northwest-Division leading Flames by two points but is just six points ahead of ninth-place Anaheim in the West.