Maatta was hit from behind by Minnesota's Nino Niederreiter midway through the second period right in front of the Wild bench. The door to the bench was open and Niederreiter collided with Maatta as Niederreiter was making his way off the ice.
The Penguins said Wednesday that Maatta will be examined again later in the day and that Maatta's injury is not related to any previous injury. The 21-year-old Maatta was limited to 20 games last season following a cancer scare and shoulder surgery. Maatta has two goals and two assists in 18 games so far this season for Pittsburgh.