The Gloucester player will undergo his operation following consultation with specialist Andy Williams and will be out of action for a number of months and will miss the start of the season.
The 25-year-old suffered damage to his left knee during Wales’s summer tour to South Africa and Gloucester’s Head Coach Dean Ryan said: “Gareth is a tremendous individual and an outstanding player – someone we wanted to build around for the future.
“This injury is obviously a significant set-back to him and the club but I have no doubts he will be back in Gloucester colours next season. He has drive, determination and a willingness to succeed and I am sure that will come through in his recovery.”
Delve made 20 appearances in all competitions for Gloucester last season following his summer move from Bath.
