GIANTS defender Chad Cornes underwent knee surgery yesterday and is expected to miss eight to 10 weeks.

GIANTS Sports Science Manager John Quinn said that the club had been monitoring Cornes' knee over the pre season and had decided to consult with surgeons.

"We decided to send Chad to Melbourne to meet with Dr David Young to investigate the cause of his knee issues.

"They discovered a cyst on Chad's right knee and decided the best cause of action was to operate. They're very happy with the results."

Cornes will return to Sydney today to begin his rehab. It is expected that he will be able to resume playing in eight to 10 weeks.