Scans have confirmed Matthew Jaensch has ruptured the Anterior Cruciate Ligament in his left knee.

Jaensch sustained the injury when he attempted to change direction and chase an opponent in the third quarter against St Kilda at Adelaide Oval on Saturday. The 25-year-old was taken from the ground on a stretcher and played no further part in the game.

Scans on Monday confirmed the Club medical staff’s diagnosis of a ruptured ACL. It’s expected Jaensch will have a traditional knee reconstruction, which carries a recovery time of 12 months.

Jaensch, who hasn’t missed a game since Round 22, 2013, has established himself as a vital part of Adelaide’s defence in the past 18 months. He enjoyed a career-best season in 2014, finishing seventh in the Crows Club Champion award.

Prior to the weekend, the creative backman ranked No.1 in the AFL for effective kicks (80) and uncontested marks (49). Regarded as one of the best kicks at West Lakes, Jaensch also leads the Crows in rebound 50ms (24).