Kangaroos' season preparations rocked by Ben Brown calf scare

North Melbourne's pre-season plans have been thrown into disarray with star forward Ben Brown reportedly being rushed to scans after dealing with calf soreness in training.

According to a Herald Sun report, Brown was forced to prematurely leave the training track on Thursday, with the Kangaroos now sweating over scans which will determine the severity of the injury.

A calf tear would see Brown struggle to appear in the Kangaroos' season-opener against St Kilda on March 22.

Since making his debut in 2014, the prolific goalkicker has been remarkably durable, appearing in all 22 games in each of the past five seasons.

The 27-year-old is the fulcrum around which the Kangaroos' forward line structure is built, bagging in excess of 60 goals in the past three seasons.

If Brown is unable to take part in the early stages of the Kangaroos season, it could see Rhyce Shaw's side vulnerable up forward, with fellow big man Nick Larkey the only viable tall option up forward.

Brown's injury concerns come after a number of his high-profile teammates have endured interrupted pre-seasons.

Skipper Jack Ziebell has been unable to train with the main group for the majority of the summer as he deals with his own calf concern, while star midfielder Jared Polec and defensive lynchpin Robbie Tarrant are both unlikely to feature in Round 1.