"It's a significant injury and he faces between six and nine months recovery," said head coach Dean Ryan. "It is very sad because he is quite a talent. The saddest thing is, is that he has lost his opportunity this year."
Gloucester have been picking through the injury list this week after skills coach and stand off Duncan McRae underwent knee surgery.
The former Australian A back had some cartilage tidied up and some bone shaved off the side of his knee. He faces six weeks recovery time and will hopefully be back in action by November 12.
Meanwhile, the club's medical team is monitoring the progress of full-back Olly Morgan, who has bleeding on the thigh. He will be out of action for another three of four weeks as he gets assessed.