Stars coach Marc Crawford wouldn't elaborate on the injuries but said both players are day to day.
"We'll have to see how they are and how they settle down tomorrow and hope they're quick healers," Crawford said.
Morrow, a member of Canada's Olympic team, went to the locker room late in the first period Saturday after blocking a shot. He played one shift in the second period before being ruled out for the third period.
"It's not that serious," Morrow said.
Lehtinen played only 3 minutes, 15 seconds of the opening period. The team later announced that Lehtinen is day to day with an undisclosed injury.
Lehtinen, a member of Finland's Olympic team, already has missed 16 games with hip and groin injuries.
ESPNDallas.com's Jeff Caplan and The Associated Press contributed to this report.