Robbie Tarrant has been a late withdrawal from North Melbourne’s semi-final side to play Sydney.

The key AFL defender will be replaced by Luke McDonald after tweaking his groin in the warm-up for the match at ANZ Stadium.

The loss is a big one for the Kangaroos, with Tarrant producing career-best form in 21 matches for his side this season.

Earlier, both sides brought in teenage talent with late changes ahead of their semi-final on Saturday night.

Kangaroos coach Brad Scott gave a call-up to forward Kayne Turner for Robbie Nahas, while Swans mentor John Longmire opted for James Rose ahead of Brandon Jack.

The winner of the semi-final will progress to play West Coast in a preliminary final next Saturday night.