Sydney Swans defender Jack Maibaum will consult a specialist after injuring his ACL.

The 20-year-old suffered the injury during a training session at Henson Park last week.

Sydney Swans Head of Football Charlie Gardiner said it’s disappointing news.

“Jack had been training really well over summer and was well primed for the season ahead, so clearly this is bitterly disappointing for Jack and for the team,” Gardiner said.

“He’ll consult a specialist today to determine the prognosis and we’ll map out a plan for his recovery from there.”

Maibaum was recruited to the Swans with selection number 45 in the 2016 AFL Draft.

He inked a one-year contract extension last October, on the back of a promising season in the NEAFL.