After the Flames' 3-0 shutout victory, head coach Geoff Ward said Markstrom is "day-to-day for a little while," according to Sportsnet's Eric Francis.
When asked postgame about Andersen's status, Leafs head coach Sheldon Keefe said the goaltender is considered day-to-day and that he doesn't "know what's going to happen from here," according to The Athletic's James Mirtle.
Markstrom was pulled from Saturday's game against the Edmonton Oilers after allowing five goals on 20 shots. It isn't clear when he suffered an injury. The 31-year-old started 10 of Calgary's last 12 games.
Andersen was able to complete his last contest, a 5-3 victory over the Montreal Canadiens on Saturday. He's started 11 of the Leafs' past 12 games.