Fernandez stayed in Minnesota during the four-day all-star break and skated to test the knee, which he injured in a game against Dallas right before the break. He practised briefly on Thursday, but left when his knee stiffened up, coach Jacques Lemaire said.
The Wild will face Calgary at home Friday night, with backup goalie Niklas Backstrom expected to play for Fernandez.
"He won't be playing, that's for sure, tomorrow," Lemaire said of Fernandez. "It will be a day-to-day thing. But I don't think he will be playing tomorrow."
Fernandez, who is 21-15-1 with a 2.58 goals-against average and .911 save percentage this season, said after practice that he was a little more optimistic.
"I'm better," he said. "I stayed here and skated throughout the break. I did what I had to do. It felt pretty good."