The Sky Blues utility man ruptured his anterior cruciate ligament in the Sydney derby against Western Sydney Wanderers on Saturday night and will undergo surgery later this week.

"It's disappointing for Rhyan but he is a strong and tough character, so I have no doubt he has the ability to come back and come back an even better player," said coach Frank Farina.

"He will be well looked after and providing he follows the advice he is given, he'll have no problems returning to the park."

The 22 year old is expected to go under the surgeon's knife on Friday and will begin his physio and rehabilitation program next week.

"It's a long road ahead but I'm positive and looking forward to getting back on my feet," said Grant.

"A number of the boys have suffered the same injury during their careers so I'm more than confident I will be able to return fitter and stronger.

"It's a blow but the physio staff at Sydney FC have been first class and I'm eager to begin my recovery as soon as possible."