Scans have confirmed a left MCL injury for North Melbourne Tasmanian Kangaroos prized trade recruit Libby Birch. 

The experienced defender sustained the injury at training on Tuesday morning. 

"This is obviously disappointing news for Libby, especially so close to the start of the AFLW season," North Melbourne general manager of women’s football Erin Lorenzini said.

"A two-time All-Australian defender, Libby was an important addition for us during last year’s trade period and has already made an impact both on and off the field over the pre-season.

"She is expected to be sidelined for at least six weeks, but we will have a better understanding of her return to play timeline as we monitor her rehab progress."

Birch, 26, began her AFLW career at the Western Bulldogs, where she played all 22 games across three seasons and won a premiership alongside her now-Roo teammates Emma Kearney, Jenna Bruton and Kim Rennie in 2018.

She joined Melbourne during the 2019 trade period, going on to play a further 55 games and win a second AFLW premiership in 2022 before arriving at Arden Street last December.