LUCKLESS Collingwood defender Matthew Scharenberg requires a second knee reconstruction that will likely rule him out for the entire 2016 season after rupturing his right anterior cruciate ligament at training on Monday.

Scharenberg, 20, ruptured his left ACL playing for Collingwood's VFL team last August, but returned to make his AFL debut in round 18 this year against Melbourne, one of four senior games he played in 2015.

Collingwood announced on Monday afternoon that scans revealed Scharenberg would require a full knee reconstruction after injuring himself "innocuously" at training.

"This is obviously disappointing for everyone but foremost for Matthew," Collingwood football director Neil Balme said.

"That said, he is only 20 years of age, he has his career before him and he is made of the right stuff. He has the mental strength and dedication to overcome a difficulty like this.

"We will look after him with all the care we can offer, to make the period before his return as smooth as possible."

Scharenberg, the No.6 pick in the 2013 NAB AFL Draft, is expected to have surgery this week.

He has had no luck with injury since joining the Pies, undergoing surgery on both feet in the 2014 pre-season, procedures that sidelined him until the second half of that season.

The South Australian signed a three-year contract extension with Collingwood in September.

His latest setback follows the departure of the Pies' second selection in the 2013 draft, No.10 pick Nathan Freeman, to St Kilda in last month's trade period.

However, the Magpies acquired that year's No.6 selection, James Aish, on the last day of the trade period.