Calgary (AB), Canada – Ski cross world championship silver medalist Julia Murray will miss the rest of the World Cup season after doctors confirmed she has a serious knee injury that will require surgery.nMurray, of Whistler, British Columbia, hurt her left knee when she landed a big jump at the Winter X Games in Aspen, Colo., in January. After a week’s rest, Murray got back on her skis and battled through pain to win the silver medal at the World Championships at Deer Valley ski resort in Park City, Utah.

However, further tests conducted last week revealed Murray has a torn anterior cruciate ligament (ACL) and she is due to undergo surgery in the coming weeks.

“I thought it was just going to be a little clean-up but it was more serious,” said Murray of doctors scoping her knee this week. “It’s hard to believe.”

Murray suffered a partial ACL tear on her left knee in January 2010, but competed at the Winter Olympics, finishing 12th.

After hurting the same knee during X Games last month, Murray sat out the finals but returned to competitive action a week later at the World Championships.

“It makes what she did at the World Championships that much more incredible,” said Eric Archer, head coach of Canada’s ski cross team.

Murray, 22, underwent further tests last week and had her knee examined by doctors.

“She has torn her previously reconstructed ACL and sustained cartilage damage,” said Dr. Stephen French, medical co-director of Alpine Canada Alpin. “She is keen to start the rehabilitation process.”