Jagr, 45, was listed as day-to-day with a lower-body injury on Wednesday and missed the club’s game against the Toronto Maple Leafs that night. He previously missed a six-game stretch from Oct. 24 to Nov. 7 with a lower-body ailment.
In 17 games with Calgary so far this season, Jagr has a goal and seven points.
The team also announced that goaltender David Rittich will get the start in net in Montreal, giving starter Mike Smith a night off on the second half of the club’s back-to-back. The 25-year-old won his first NHL start on Nov. 25 against the Colorado Avalanche, and saw one period of playing time as backup to Smith in Saturday night’s loss to the Oilers.
Forward Matthew Tkachuk’s status is still unclear, as he is set to have a hearing with the NHL’s player safety department on Thursday.