Nylander left Thursday's game versus the Golden Knights after aggravating his previous lower-body injury, Luke Fox of Sportsnet reports.
Nylander previously missed six games due to the issue, and he could be in line for another absence. The 29-year-old's at 17 goals and 48 points over 37 appearances this season, so any time missed will take some power out of the Maple Leafs' lineup. His status for Saturday in Winnipeg has yet to be determined, but expect Toronto to take things cautiously with the star forward.