The Western Bulldogs have confirmed youngster Roarke Smith has a ruptured anterior cruciate ligament.

Smith went to ground while contesting a ball during the third quarter of his side's JLT Community Series loss to the Lions and was help off by a trainer.

It is a huge blow for the 20-year-old, who also underwent a knee reconstruction in August 2015.

The club confirmed on Friday afternoon he will undergo a traditional knee reconstruction.

โ€œScans today confirmed Roarke has ruptured his anterior cruciate ligament and he will undergo a traditional reconstruction on Monday,"ย Bulldogs Head Physiotherapist and Medical Services Manager Chris Bell said.

โ€œRoarkeโ€™s a highly regarded member of our playing group and weโ€™ll put all our efforts into supporting him through his recovery.โ€

Smith, the No.5 pick in 2014 Rookie Draft, made his debut in round 22, 2015 and has played two senior games for the clubs.