North Melbourne ruckman Braydon Preuss has been reported for striking Geelong's Jackson Thurlow in the back with his knee.
The incident happened early in the second quarter, as Thurlow took a mark after a kick-in from Marley Williams.
Preuss was late to the contest and struck Thurlow with his knee, giving away a 50-metre penalty and getting reported in the process.
The game against Geelong is Preuss' second in his AFL career after making his debut against West Coast last weekend.
Preuss was a late inclusion for Sunday's game after Todd Goldstein was withdrawn with a lingering ankle injury.