Roos sweating on fitness of key duo

North Melbourne is sweating on the fitness of forward Ben Brown and key defender Scott Thompson ahead of Saturday's crucial clash with Hawthorn.

Thompson was forced from the field in the final quarter due to a groin injury and did not return, while Brown left the field in the second term after re-injuring his heavily strapped left knee in a marking contest.

If Brown misses, the Ross will be forced to field a side missing three of its first choice forwards, with Jarrad Waite (hip) and Mason Wood (knee) also out with injury.

Meanwhile, the Kangaroos could also be without Jed Anderson for the clash against his old side, with the former Hawk reported for a bump on Lin Jong.