The 29-year-old tore a pectoral muscle during a gym session on Friday, indefinitely ruling him out of playing his first game since August 2018.

The Kangaroos are weighing up whether to book him in for surgery, which would all but cost him any chance of playing an AFL game in 2020.

Before his latest injury setback, Daw was on the verge of a remarkable first AFL appearance since suffering serious hip and pelvic injuries in a fall from Melbourne's Bolte Bridge in December 2018.

He was picked to play in the Roos' round one game against St Kilda in March but was a late withdrawal after coming down with a minor cold.

North's football manager Brady Rawlings highlighted the disappointment of losing such a valuable asset, but refused to rule out the chances of Daw playing this year.

"Maj was doing his weights program and felt a sharp pain on his right side during a chest exercise," Rawlings said.

"He was sent for scans and the imaging showed a tear.

"We are seeking expert opinions as to whether surgery will be required and will make a call on that in the coming days.

"Majak has had an unfortunate run with injury of late but we will support him and ensure he can recover well, and hopefully build up to playing games again this year."

Only last week, Roos coach Rhyce Shaw spoke of how impressive Daw's return to training had been following the AFL shutdown period.

The player was firmly in the selection mix for a spot in the Roos' back-six, along with Josh Walker, Sam Durdin and Ben McKay, for their round-two trip to face last year's grand finalist GWS on June 14.

Daw has played 50 games during a stop-start career which began in 2013.

His best season was 2018 after making a permanent switch to defence, playing 18 games for the Roos and earning 'elite' status from Champion Data's ranking system.

Australian Associated Press