Majak Daw has undergone arthroscopic surgery this arvo after injuring his right knee at training on Monday.
In a statement North say that the 25-year-old was completing straight-line running when he reported some discomfort to medical staff.
“There was no warning of any issues prior to Monday so this was an unexpected and unfortunate setback,” GM Football Cameron Joyce said.
“We discovered a tear in his meniscus so he was immediately referred to a specialist.”
“It’s too difficult to put a timeframe on his return to full fitness at this stage, but we are confident he’ll be available in the opening rounds of the season,” Joyce said.