Adelaide has confirmed young defender Jordan Elsey has ruptured his anterior cruciate ligament.

It is a cruel blow for the 22-year-old who only returned from an ACL injury in the same knee in November last year.

“Jordan has ruptured the ACL in his left knee. It was a non-contact injury," club doctor James Ilic said.

“We're discussed the situation with Jordan and his family about what we believe to be the best course of action, and the decision has been made that we will perform a full reconstruction as soon as possible.”

He enjoyed a breakout season in 2015-16 upon his return from injury, making 17 appearances for the Reds en route to the A-League title. The Adelaide local has played 27 matches and scored one goal for United since joining the club in 2013.